Abstract: A honeycomb structure 20 according to the present invention includes: a ceramic honeycomb structure portion 10 including: an outer peripheral wall 12; a partition wall 13, the partition wall 13 defining a plurality of cells 16; and a pair of electrode layers 14a, 14b each arranged so as to extend in a form of a band on an outer surface of the outer peripheral wall 12, across a central axis of the honeycomb structure portion 10, wherein the honeycomb structure portion 10 is provided in an end portion region(s) extending in a direction from the one end face and/or the other end face to a center in a flow path length direction of the honeycomb structure portion 10, and the honeycomb structure portion 10 comprises at least one low porosity portion 4 having a lower porosity than an average porosity of the whole honeycomb structure portion 10.

Abstract: A honeycomb structure 20 according to the present invention includes: a honeycomb structure portion 10 including: an outer peripheral wall 12; a partition wall 13 arranged on an inner side of the outer peripheral wall 12, the partition wall 13 defining a plurality of cells 16 each extending from one end face to other end face to form a flow path; and a pair of electrode layers 14a, 14b arranged on a surface of the outer peripheral wall 12 of the honeycomb structure portion 10, the pair of electrode layers 14 being provided so as to face each other across a central axis of the honeycomb structure portion 10. The honeycomb structure portion 10 is made of ceramics having an NTC property, and the pair of electrode layers are made of a material having a PTC property.

Abstract: An electric heating type support includes: a pillar shaped honeycomb structure being configured to a ceramic, including: an outer peripheral wall; and partition walls disposed on an inner side of the outer peripheral wall, the partition walls defining a plurality of cells, each of the cells extending from one end face to other end face to form a flow path; at least one electrode layer disposed on a surface of the outer peripheral wall of the pillar shaped honeycomb structure; and at least one electrode connecting portion provided on the at least one electrode layer, the at least one electrode connecting portion being connectable to a metal connector. The at least one electrode connecting portion has at least one independent rising portion, and a height of the at least one electrode connecting portion from a surface of the at least one electrode layer is from 1 to 6 mm.

Abstract: An electrically heating support includes: a pillar shaped honeycomb structure including: an outer peripheral wall; and a partition wall disposed on an inner side of the outer peripheral wall, the partition wall defining a plurality of cells, each of the plurality of cells extending from one end face to the other end face to form a flow path; and a pair of electrode layers disposed so as to face each other across a central axis of the honeycomb structure, each of the electrode layers being disposed on a surface of the outer peripheral wall of the honeycomb structure; and a metal terminal provided on each of the electrode layers. The honeycomb structure includes a ceramic having a PTC property, and the electrode layers include a ceramic having an NTC property.

Abstract: An electric heating type support includes: a pillar shaped honeycomb structure being configured to a ceramic, including: an outer peripheral wall; and partition walls disposed on an inner side of the outer peripheral wall, the partition walls defining a plurality of cells, each of the cells extending from one end face to other end face to form a flow path; at least one electrode layer disposed on a surface of the outer peripheral wall of the pillar shaped honeycomb structure; and at least one electrode connecting portion provided on the at least one electrode layer, the at least one electrode connecting portion being connectable to a metal connector. The at least one electrode connecting portion has at least one independent rising portion, and a height of the at least one electrode connecting portion from a surface of the at least one electrode layer is from 1 to 6 mm.

Abstract: A honeycomb structure has a pillar-shaped honeycomb structure body having porous partition walls which defines cells which forms a passage of liquid extended from an inflow end face toward an outflow end face, a circumferential wall arranged to surround a circumference of the partition walls. The honeycomb structure body has an outermost circumference cell structure including a complete cell arranged at the outermost circumference of the honeycomb structure body, a center cell structure formed by the cells arranged at a center part at an inner side to the outermost circumference cell structure, and a boundary wall arranged at a boundary part between the outermost circumference cell structure and the center cell structure. The outermost circumference cell structure and the center cell structure are formed as different structures to each other, and a thickness of the boundary wall is set to be thicker than a thickness of the circumferential wall.

Abstract: A honeycomb structure has a pillar-shaped honeycomb structure body having porous partition walls which defines cells which forms a passage of liquid extended from an inflow end face toward an outflow end face, a circumferential wall arranged to surround a circumference of the partition walls. The honeycomb structure body has an outermost circumference cell structure including a complete cell arranged at the outermost circumference of the honeycomb structure body, a center cell structure formed by the cells arranged at a center part at an inner side to the outermost circumference cell structure, and a boundary wall arranged at a boundary part between the outermost circumference cell structure and the center cell structure. The outermost circumference cell structure and the center cell structure are formed as different structures to each other, and a thickness of the boundary wall is set to be thicker than a thickness of the circumferential wall.

Abstract: A gas duct includes a ceramic honeycomb structure includes a metal case, a ceramic honeycomb structure accommodated in the metal case, and a holding member placed between the outer surface of the ceramic honeycomb structure and the inner surface of the metal case. The holding member has, at the two ends, to-be-connected areas engageable to each other and is wound round the outer surface of the ceramic honeycomb structure in such a way that the to-be-connected areas of the two ends are engaged to each other and that the connected area and its vicinity face the partition wall of each cell constituting the honeycomb structure. In the gas duct, even when the ceramic honeycomb structure has thin partition walls, the honeycomb structure is not broken when it is accommodated in a metal case, i.e. during the canning.

Abstract: A gas duct having a honeycomb structure includes: a metal case, a honeycomb structure accommodated in the metal case, a holding member placed between the outer surface of the honeycomb structure and the inner surface of the metal case, and a cone fitted to the inner surface of the metal case at one or both openings of the metal case, wherein the circumference of one or both end faces of the honeycomb structure is allowed to abut on the cone. The gas duct having a honeycomb structure can effectively utilize the whole volume of the honeycomb structure, is low in pressure loss, and inexpensive.

Abstract: A gas duct having a honeycomb structure includes: a metal case, a honeycomb structure accommodated in the metal case, a holding member placed between the outer surface of the honeycomb structure and the inner surface of the metal case, and a cone fitted to the inner surface of the metal case at one or both openings of the metal case, wherein the circumference of one or both end faces of the honeycomb structure is allowed to abut on the cone. The gas duct having a honeycomb structure can effectively utilize the whole volume of the honeycomb structure, is low in pressure loss, and is low also in cost.