Honeycomb structure and method for manufacturing the same

Abstract

A honeycomb structure includes porous partition walls via which a plurality of cells constituting through channels for a fluid are partitioned; and an outer peripheral wall positioned in the outermost periphery of the structure. Open frontal areas of predetermined cells in an end face of the structure on a fluid inlet side thereof and open frontal areas of remaining cells in an end face of the structure on a fluid outlet side thereof have plugged portions. The outward end faces of the plugged portions are flat, the plugged portions do not have any bubble having a diameter of 0.3 mm or more, and a value obtained by dividing the standard deviation of the plugging depths of the plugged portions by the average plugging depth of the plugged portions is 0.15 or less.

1 . A honeycomb structure comprising: porous partition walls via which a plurality of cells constituting through channels for a fluid are partitioned; and an outer peripheral wall positioned in the outermost periphery of the structure, open frontal areas of predetermined cells in an end face of the structure on a fluid inlet side thereof and open frontal areas of remaining cells in an end face of the structure on a fluid outlet side thereof being provided with plugged portions,
 wherein the outward end faces of the plugged portions are flat,   the plugged portions do not have any bubble having a diameter of 0.3 mm or more, and   a value obtained by dividing the standard deviation of the plugging depths of the plugged portions by the average plugging depth of the plugged portions is 0.15 or less.   
     
     
         2 . The honeycomb structure according to  claim 1 , wherein the depths of the plugged portions are from 3 to 12 mm. 
     
     
         3 . The honeycomb structure according to  claim 1 , wherein the predetermined cells and the remaining cells are alternately arranged. 
     
     
         4 . The honeycomb structure according to  claim 1 , wherein the material of the partition walls and the plugged portions contains at least one selected from the group consisting of cordierite, mullite, alumina, silicon carbide and aluminum titanate. 
     
     
         5 . A method for manufacturing a honeycomb structure in which the honeycomb structure according to  claim 1  is manufactured, comprising:
 a masking process of attaching a sheet to one end face of a formed honeycomb article comprising porous partition walls via which a plurality of cells constituting through channels for a fluid are partitioned and an outer peripheral wall positioned in the outermost periphery of the article, and making holes in the positions of the sheet superimposed on the cells in which plugged portions are to be formed; 
 a first press-in process of pressing the end of the formed honeycomb article, to which the sheet is attached, into a container in which a plugging material is received, to press the plugging material into the cells via the one end face of the formed honeycomb article through the holes formed in the sheet; and 
 a second press-in process of moving, along the surface of the sheet, a press-in jig including a pressurization member having a hardness of 60 to 90 degrees, having a plate-like shape, chamfered along one side of the shape perpendicular to a thickness direction and having a flat face disposed adjacent to the chamfered face in parallel with the thickness direction, in a state where an angle between a pressurization face which is the chamfered face and the sheet is from 15 to 50°, to press, by the pressurization face, the plugging material supplied between the sheet and the pressurization face into the cells in which the plugging material is charged, over the plugging material, through the holes formed in the sheet. 
 
     
     
         6 . The method for manufacturing the honeycomb structure according to  claim 5 , wherein the length of the flat face in the thickness direction of the pressurization member is a length of 20 to 40% of the thickness of the pressurization member. 
     
     
         7 . The method for manufacturing the honeycomb structure according to  claim 5 , wherein the material of the pressurization member contains a rubber.