A honeycomb structure includes honeycomb segments, bonding layers and a circumferential wall. The bonding layers include bottomed-hollow voids which extend toward an internal side in an axial direction from an end face of the honeycomb structure and which are formed at at least one of intersections, and a ratio of a depth of each void in the axial direction to a length of each honeycomb segment in the axial direction is 5% or more.

A pillar-shaped honeycomb structure body of a honeycomb structure includes a circumferential cell structure, a central cell structure and a boundary wall therebetween. On a surface orthogonal to the cells there are a circumferential reinforcing region having the partition wall thicker than a basic partition wall thickness in the circumferential cell structure and existing outside a range of a distance from a centroid of the surface; and at least one of a first boundary reinforcing region having the partition wall thicker than the basic partition wall thickness and existing in a range of a distance from the centroid within a range of the circumferential cell structure and a second boundary reinforcing region having the partition wall thicker than a basic partition wall thickness in the central cell structure and existing outside of a range of a distance from the centroid within a range of the central cell structure.

A tray including a plate-shaped portion for arranging a plurality of prismatic honeycomb structures having an outer peripheral side surface and partition walls provided on an inner peripheral side of the outer peripheral side surface, the partition walls partitioning a plurality of cells forming flow paths from a first end surface to a second end surface, the plate-shaped portion including: a plurality of corrugated plate-shaped placing portions for placing the prismatic honeycomb structures with the outer peripheral side surface in contact with the placing portions; flat plate-shaped non-placing portions adjacent to each of the corrugated plate-shaped placing portions; and partition walls erected between adjacent corrugated plate-shaped placing portions to prevent the outer peripheral side surfaces of adjacent prismatic honeycomb structures from contacting each other.

A tray including a plate-shaped portion for arranging a plurality of prismatic honeycomb structures having an outer peripheral side surface and partition walls provided on an inner peripheral side of the outer peripheral side surface, the partition walls partitioning a plurality of cells forming flow paths from a first end surface to a second end surface, the plate-shaped portion including: a plurality of corrugated plate-shaped placing portions for placing the prismatic honeycomb structures with the outer peripheral side surface in contact with the placing portions; flat plate-shaped non-placing portions adjacent to each of the corrugated plate-shaped placing portions; and partition walls erected between adjacent corrugated plate-shaped placing portions to prevent the outer peripheral side surfaces of adjacent prismatic honeycomb structures from contacting each other.

A honeycomb structure includes a honeycomb segment bonded member including; a plurality of prismatic columnar shaped honeycomb segments; and a bonding layer bonding the segments, wherein one honeycomb segment has a bulge on one side face, extending in an axial direction, another honeycomb segment has a recess on one side face, extending in the axial direction, the one honeycomb segment and the another are disposed adjacent and bonded to each other via the bonding layer with the bulge inserted in the recess, length of the bulge is smaller than length of the one side face of the one honeycomb segment, length of the recess is smaller than length of the one side face of the another honeycomb segment, a base part of the bulge is defined with a bent side face, an angle between an imaginary bottom face and the bent side face of the bulge being 60° or more.

A honeycomb structure includes a honeycomb segment bonded member including; a plurality of prismatic columnar shaped honeycomb segments; and a bonding layer bonding the segments, wherein one honeycomb segment has a bulge on one side face, extending in an axial direction, another honeycomb segment has a recess on one side face, extending in the axial direction, the one honeycomb segment and the another are disposed adjacent and bonded to each other via the bonding layer with the bulge inserted in the recess, length of the bulge is smaller than length of the one side face of the one honeycomb segment, length of the recess is smaller than length of the one side face of the another honeycomb segment, a base part of the bulge is defined with a bent side face, an angle between an imaginary bottom face and the bent side face of the bulge being 60° or more.

Provided is a porous honeycomb filter comprising a porous first cell wall that permits exhaust gas to permeate, a second cell wall that permits exhaust gas to permeate than the first cell wall, and a cell that is surrounded by the first cell wall and the second cell wall to form an extending gas flow passage. The second cell wall has a smaller porosity than the first cell wall.

Provided is a porous honeycomb filter comprising a porous first cell wall that permits exhaust gas to permeate, a second cell wall that permits exhaust gas to permeate than the first cell wall, and a cell that is surrounded by the first cell wall and the second cell wall to form an extending gas flow passage. The second cell wall has a smaller porosity than the first cell wall.

A filter including a plurality of pillar-shaped honeycomb structure segments made of porous ceramics, side faces of the segments being bonded together via a bonding material, wherein each of the pillar-shaped honeycomb structure segments includes an outer peripheral side wall, and partition walls partitioning a plurality of cells extending from a first end face to a second end face, and in each of the pillar-shaped honeycomb structure segments, an average porosity of the outer peripheral side wall is lower than that of the partition walls.

A filter including a plurality of pillar-shaped honeycomb structure segments made of porous ceramics, side faces of the segments being bonded together via a bonding material, wherein each of the pillar-shaped honeycomb structure segments includes an outer peripheral side wall, and partition walls partitioning a plurality of cells extending from a first end face to a second end face, and in each of the pillar-shaped honeycomb structure segments, an average porosity of the outer peripheral side wall is lower than that of the partition walls.