| 摘要 |
PROBLEM TO BE SOLVED: To provide a honeycomb structure whose thermal shock resistance can be improved while sufficiently securing exhaust gas cleaning performance.SOLUTION: A honeycomb structure 1 has a plurality of cell density regions 2 configured so that the cell density is changed step by step in the radial direction thereof. A border wall 14 is disposed between the adjacent cell density regions 2. The plurality of cell density regions 2 include the high cell density region 2a having the highest cell density among the cell density regions except for the outermost cell density region 2 and the low cell density region 2b having the lowest cell density among the cell density regions except for the innermost cell density region 2. When the solid volume of the honeycomb structure is defined as V on the assumption that the entire honeycomb structure 1 is constituted of the high cell density region 2a, the solid volume of the high cell density region 2a of the honeycomb structure 1 is defined as Va; the solid volume of the low cell density region 2b is defined as Vb; and the solid volume of the border wall 14 that separates the low cell density region 2b from the cell density region present just on the inside thereof is defined as Vs, the relationship of V-Va≥Vb+Vs is satisfied. |
