| 摘要 |
PROBLEM TO BE SOLVED: To provide a honeycomb structure in which the early activation and the heat insulation capability are combined, as well as the purification capability can be improved.SOLUTION: The honeycomb structure 1 includes a plurality of cell walls 2, and a plurality of cell holes 3 surrounded by the plurality of cell walls 2, and passes the exhaust gas discharged from an internal combustion engine through the plurality of cell holes 3 for purification. In at least a portion of the plurality of cell holes 3, there are formed, in axial direction X, an upstream side protrusion portion 41 disposed in upstream side from the central part 12 of the honeycomb structure 1, and a downstream side protrusion portion 42 disposed in downstream side from the central part 12 of the honeycomb structure 1. The upstream side protrusion portion 41 is formed so as the heat capacity per unit volume to be smaller than the cell wall 2, and the downstream side protrusion portion 42 is formed so as the heat capacity per unit volume to be larger than the upstream side protrusion portion 41.SELECTED DRAWING: Figure 3 |
