Patent 7429416 was granted and assigned to NGK Insulators on September, 2008 by the United States Patent and Trademark Office.
There is disclosed a honeycomb structure which solves a problem of antinomy that it is difficult to satisfy both of a high temperature rise performance and a high thermal capacity at the same time and which is disposed at a previous stage of a filter for trapping particulate matters (PM) discharged from a diesel engine so that regeneration of the PM trapped by the filter can smoothly be completed and an exhaust gas can efficiently be purified. In a honeycomb structure in which a plurality of cells arranged in parallel with one another to communicate between two end surfaces of the honeycomb structure are formed by a plurality of partition walls, the plurality of partition walls are made of a ceramic, and constituted of partition walls having two or more types of thicknesses.