| abstract |
A honeycomb structure comprising a honeycomb structural body having an inlet end surface and an outlet end surface, the honeycomb structural body: a porous partition wall that defines a plurality of cells that extend from the inlet end surface to the outlet end surface and serve as a through-channel for a fluid; and a peripheral wall arranged to surround the partition wall, the honeycomb structural body having a dense part, the dense part comprising a central region of the inlet end face and a part of the central region of the inlet end surface along an axial direction of the honeycomb structural body and the dense part has a porosity change ratio of 2 to 8%, the porosity change ratio being calculated with the following formula (1), and the honeycomb structural body has a part with increasing outside diameter at least on a part of the honeycomb structure body in the axial direction, the part with increasing Outer diameter has an outer diameter of a plane orthogonal to the axis direction of the honeycomb structural body, which increases from the inlet end surface to the outlet end surface, and the honeycomb structural body has a change ratio of the average diameter of 0.2 to 3%, the change ratio of the average total diameter is calculated using the following formula (2), ( 1 - Px / Py ) × 100, where in formula (1) Px denotes the porosity (%) at the middle region of the inlet end face and Py denotes the porosity (%) of a peripheral region of the inlet end face which is not the middle region, ( 1 - Dx / Dy ) × 100, where in formula (2) Dx denotes an average diameter (mm) of the inlet end face of the honeycomb structural body and Dy denotes an average diameter (mm) of the outlet end surface of the honeycomb structural body. |