Honeycomb formed body and method for producing honeycomb structure

A honeycomb formed body containing a ceramics raw material, the honeycomb formed body comprising:

• a pillar shaped honeycomb structure portion having a plurality of rectangular cells, the plurality of rectangular cells being defined by partition walls and extending from a first end face to a second end face to form flow paths;
• an outer peripheral portion comprising:
• outer peripheral portions X where the partition walls are covered with an outer peripheral wall;
• and outer peripheral portions Y where the partition walls are exposed;
• wherein the honeycomb formed body has a cross-sectional portion satisfying the following four conditions:
• the outer peripheral portions Y are arranged over four portions:
• a length portion LA of 3% or more and 14% or less of an outer peripheral length including an intersection portion between a straight line A and the outer peripheral portion, wherein the outer peripheral wall is not present;
• a length portion LB of 3% or more and 14% or less of the outer peripheral length including an intersection portion between a straight line B and the outer peripheral portion, wherein the outer peripheral wall is not present;
• a length portion LC of 3% or more and 14% or less of the outer peripheral length including an intersection portion between a straight line C and the outer peripheral portion, wherein the outer peripheral wall is not present;
• and a length portion LD of 3% or more and 14% or less of the outer peripheral length including an intersection portion between a straight line D and the outer peripheral portion, wherein the outer peripheral wall is not present;
• in which, when observing the honeycomb formed body in a cross section perpendicular to a height direction, the straight line A, the straight line B, the straight line C, and the straight line D respectively represent four straight lines extending from a center of gravity of a rectangular cell where of the plurality of rectangular cells the center of gravity is present at a position closest to a center of gravity of the cross section, through four corners of the rectangular cell of the plurality of rectangular cells, toward an outer periphery;
• the outer peripheral portions X and the outer peripheral portions Y are alternately arranged in an outer peripheral direction;
• each of the outer peripheral portions X comprises a tapered portion having a gradually decreasing thickness of the outer peripheral wall toward a boundary portion with an adjacent outer peripheral portion Y;
• and
• the tapered portion requires a length equal to or more than one time of an average cell pitch in the outer peripheral direction until thickness of the outer peripheral wall is halved.