US Patent 7678439 Honeycomb structure and die for forming honeycomb structure

A honeycomb structure has a cell structure section 3 an outer circumferential wall section 4. The cell structure section 3 includes a first partition wall group having partition walls 1a positioned in parallel and a second partition wall group having partition walls 1b which intersect the partition walls of the first partition wall group at right angles and are positioned in parallel. In this honeycomb structure, the partition wall intervals of the partition walls 1a and 1b of each partition wall group positioned in parallel are varied stepwise in at least a part of the cell structure section 3, and all the partition walls 1a and 1b have such a ratio of the cell side length to the partition wall thickness that the partition wall can withstand pressure during canning. The honeycomb structure has increased isostatic strength and thermal shock resistance and can be manufactured at low cost.