Patent 7858168 was granted and assigned to NGK Insulators on December, 2010 by the United States Patent and Trademark Office.
There is disclosed a honeycomb structure in which while sufficiently maintaining a collection efficiency and a bonding strength of a plugging portion, a thermal shock resistance is improved. A plugging portion 32 is formed in the end of each cell 3 of a honeycomb structure 1, and a gap 34 having a size of 20 μm or more is formed between the plugging portion 32 and each partition wall 2. Moreover, the length of the gap 34 in the axial direction is 50% or more and less than 95% of the length of the plugging portion 32 in the axial direction, the length of the gap in a face vertical to the axial direction is 20% or more and 50% or less of the length of the inner peripheral surface of the cell 3, and the gaps are formed in at least ⅓ of the plugging portions 32.