| 主权项 |
1. A honeycomb filter comprising:
a plurality of cells through which exhaust gas is to flow and which include exhaust gas introduction cells and exhaust gas emission cells, the exhaust gas introduction cells each having an open end at an exhaust gas introduction side and a plugged end at an exhaust gas emission side, the exhaust gas emission cells each having an open end at the exhaust gas emission side and a plugged end at the exhaust gas introduction side, the exhaust gas introduction cells and the exhaust gas emission cells each having a uniform cross sectional shape except for a plugged portion in a cross section perpendicular to the longitudinal direction of the plurality of cells thoroughly from the end at the exhaust gas introduction side to the end at the exhaust gas emission side; porous cell walls defining rims of the plurality of cells, each of the exhaust gas emission cells being adjacently surrounded fully by the exhaust gas introduction cells across the porous cell walls; the exhaust gas introduction cells including first exhaust gas introduction cells and second exhaust gas introduction cells, each of the second exhaust gas introduction cells having a cross sectional area larger than a cross sectional area of each of the first exhaust gas introduction cells in the cross section perpendicular to the longitudinal direction of the plurality of cells; each of the exhaust gas emission cells having a cross sectional area equal to or larger than the cross sectional area of each of the second exhaust gas introduction cells in the cross section perpendicular to the longitudinal direction of the plurality of cells; and each of the first exhaust gas introduction cells having the cross sectional area equal to or smaller than 0.7 mm2 in the cross section perpendicular to the longitudinal direction of the plurality of cells. |
