Abstract: A plugged honeycomb structure includes: a honeycomb substrate and a plugging portion, and is configured to trap particulate matter included in fluid flowing from an inflow side end face to an outflow side end face. The partition wall includes, as raw materials, particulates of a base material and a binder and having a melting point lower than that of the base material, the base material has a particle diameter in a range of 5 ?m to 60 ?m, a mass ratio of the binder to a total mass of the raw material of the base material and the binder is in a range of 22 mass % to 45 mass %, and the cells include round cells as a part, the round cells being defined by a circular-arc partition wall having a circular-arc shape that is at least a part of the partition wall to have a circular shape or the like.

Abstract: A honeycomb structure includes: a honeycomb structure body; and a convex part that protrudes outward from a part of circumference of the honeycomb structure body. The convex part surrounds the circumference of the honeycomb structure body like a ring. The convex part is of a tapered shape at least at one end having a tapered face. The convex part has a circumference coating layer making up the tapered face. The convex part has a maximum thickness of 1 to 20 mm, and a rough-face region on the tapered face, the rough-face region having surface roughness of 5 to 70 ?m. The rough-face region has a total of a rough-face region angle of 108° or more. An inclination angle formed between the tapered face and the extending direction of the cells is 10 to 80 degrees.

Abstract: A plugged honeycomb structure includes: a honeycomb substrate and a plugging portion, and is configured to trap particulate matter included in fluid flowing from an inflow side end face to an outflow side end face. The partition wall includes, as raw materials, particulates of a base material and a binder and having a melting point lower than that of the base material, the base material has a particle diameter in a range of 5 ?m to 60 ?m, a mass ratio of the binder to a total mass of the raw material of the base material and the binder is in a range of 22 mass % to 45 mass %, and the cells include round cells as a part, the round cells being defined by a circular-arc partition wall having a circular-arc shape that is at least a part of the partition wall to have a circular shape or the like.

Abstract: A honeycomb structure includes: a honeycomb structure body; and a convex part that protrudes outward from a part of circumference of the honeycomb structure body. The convex part surrounds the circumference of the honeycomb structure body like a ring. The convex part is of a tapered shape at least at one end having a tapered face. The convex part has a circumference coating layer making up the tapered face. The convex part has a maximum thickness of 1 to 20 mm, and a rough-face region on the tapered face, the rough-face region having surface roughness of 5 to 70 ?m. The rough-face region has a total of a rough-face region angle of 108° or more. An inclination angle formed between the tapered face and the extending direction of the cells is 10 to 80 degrees.

Abstract: A honeycomb structure including a honeycomb structure body, first plugging portions, and second plugging portions. The honeycomb structure body has a porous partition wall. The first plugging portions are disposed at an outflow side end face of inlet cells and an inflow side end face of outlet cells. The inlet cells are the predetermined cells of the honeycomb structure body. The outlet cells are the residual cells of the honeycomb structure body. The second plugging portions are not fired. The first plugging portions form a checkered pattern at the inflow side end face and the outflow side end face. The number of the second plugging portions is within 3% of the number of cell open ends where the first plugging portions are not formed, on both end faces of the honeycomb structure body.

Abstract: Disclosed is a honeycomb structure that hardly generates ring cracks; the honeycomb structure includes a honeycomb basal body having porous partition walls defining a plurality of cells that become through channels of a fluid; and a ring-shaped convex portion being a ring of convex portion surrounding an outer periphery of the honeycomb basal body over the whole periphery; and the ring-shaped convex portion is disposed to project outwardly from the outer periphery of the honeycomb basal body and to cover a part of the outer periphery of the honeycomb basal body, the shapes of both end portions of the ring-shaped convex portion are tapered shape, and a thickness of the ring-shaped convex portion in a cross section perpendicular to an extending direction of the cells is from 3 to 20 mm.

Abstract: A honeycomb structure includes a honeycomb structure body constituted of a first region which is an inside region and a second region which is an outside region surrounding a periphery of the first region. An open area ratio in the first region is 83% or more and a porosity of partition walls is from 20 to 60%. A thickness t1 of the partition walls constituting the first region is 0.11 mm or less, a thickness t2 of the partition walls constituting the second region is larger than the thickness t1 of the partition walls, a ratio (t3/t1) between a thickness t3 of the partition walls forming first complete cells from the outermost periphery of the honeycomb structure body toward a center thereof in the second region and the thickness t1 of the partition walls is from 1.2 to 1.4, and a partition wall strength index A is 4.0 or more.

Abstract: There is disclosed a honeycomb structure in which a ring crack is not easily generated. A honeycomb structure includes a honeycomb substrate, and a bulging portion continuously or intermittently surrounding, in a ring shape, at least a part of an outer periphery of the honeycomb substrate. The outer periphery of the honeycomb substrate has one or a plurality of stress relaxing portions which are crevices each having an open end in the surface over a region of ?5 to +10 mm or less from a reference bonded portion to a tapered surface, and a total of lengths of all the stress relaxing portions is 3% or more of a circumferential length of the honeycomb substrate.

Abstract: Provided is a honeycomb structure 1 including a honeycomb structure body, first plugging portions, and second plugging portions. The honeycomb structure body has a porous partition wall. The first plugging portions are disposed at an outflow side end face of inlet cells and an inflow side end face of outlet cells. The inlet cells are the predetermined cells of the honeycomb structure body. The outlet cells are the residual cells of the honeycomb structure body. The second plugging portions are not fired. The first plugging portions form a checkered pattern at the inflow side end face and the outflow side end face. The number of the second plugging portions is within 3% of the number of cell open ends where the first plugging portions are not formed, on both end faces of the honeycomb structure body.

Abstract: There is disclosed a honeycomb structure in which a ring crack is not easily generated. A honeycomb structure includes a honeycomb substrate, and a bulging portion continuously or intermittently surrounding, in a ring shape, at least a part of an outer periphery of the honeycomb substrate. The outer periphery of the honeycomb substrate has one or a plurality of stress relaxing portions which are crevices each having an open end in the surface over a region of ?5 to +10 mm or less from a reference bonded portion to a tapered surface, and a total of lengths of all the stress relaxing portions is 3% or more of a circumferential length of the honeycomb substrate.

Abstract: A honeycomb structure includes a honeycomb structure body constituted of a first region which is an inside region and a second region which is an outside region surrounding a periphery of the first region. An open area ratio in the first region is 83% or more and a porosity of partition walls is from 20 to 60%. A thickness t1 of the partition walls constituting the first region is 0.11 mm or less, a thickness t2 of the partition walls constituting the second region is larger than the thickness t1 of the partition walls, a ratio (t3/t1) between a thickness t3 of the partition walls forming first complete cells from the outermost periphery of the honeycomb structure body toward a center thereof in the second region and the thickness t1 of the partition walls is from 1.2 to 1.4, and a partition wall strength index A is 4.0 or more.

Abstract: There are disclosed a honeycomb structure hardly generates ring cracks; and a honeycomb structure 100 includes a honeycomb basal body 4 having porous partition walls 1 defining a plurality of cells 2 to become through channels of a fluid; and a ring-shaped convex portion 10 being a ring of convex portion surrounding an outer periphery of the honeycomb basal body 4 over the whole periphery; and the ring-shaped convex portion 10 is disposed to project outwardly from the outer periphery of the honeycomb basal body 4 and to cover a part of the outer periphery of the honeycomb basal body 4, the shapes of both end portions of the ring-shaped convex portion are tapered shape, and a thickness of the ring-shaped convex portion 10 in a cross section perpendicular to an extending direction of the cells 2 is from 3 to 20 mm.