US Patent 7858169 Honeycomb segment

A honeycomb segment containing outer walls and porous partition walls disposed inside the outer walls has a structure where first cells each open in one end portion on one side and plugged in the other end portion on the other side and second cells each plugged in one end portion on one side and open in the other end portion on the other side are alternately disposed, a cross-sectional area of the first cells in a cross section cut along a plane perpendicular to a longitudinal direction of the cells is larger than that of the second cells, and the first cells and the second cells are alternately disposed in a first direction and in a second direction perpendicular to the first direction in the cross section, and the outer walls are linearly formed so as to have a uniform thickness except for corner portions.