Method for producing ceramic honeycomb body

1. A method for producing a ceramic honeycomb body having large numbers of longitudinal cells partitioned by cell walls, with its peripheral portion removed by machining, comprising

rotatably holding said ceramic honeycomb body on a main axis of a lathe, and rotating said ceramic honeycomb body around said main axis, to remove a peripheral portion of said ceramic honeycomb body by machining with a cutting tool;

said lathe comprising a first fixing jig and second fixing jig on said main axis, said second fixing jig substantially opposing said first fixing jig;

each of said first and second fixing jigs having an abutting portion opposing each other, said abutting portion having a smaller outer shape than that of the end surface of the ceramic honeycomb body, and said abutting portion having a substantially flat abutting surface perpendicular to the main axis; and

said ceramic honeycomb body being held by pressing said abutting surfaces of said first and second fixing jigs to both end surfaces of said ceramic honeycomb body, such that the center axis of said ceramic honeycomb body is substantially in alignment with the main axis of the lathe; and

wherein said abutting portions are detachable from said fixing jigs and made of resin;

wherein said abutting surface has surface roughness (maximum height Rz) of 10-500 μm; and

wherein an area ratio of said abutting surface to a cross section of said abutting portion perpendicular to said main axis is 30-100%.

2. The method for producing a ceramic honeycomb body according to claim 1 , wherein the main axis of said lathe is substantially vertical.

3. The method for producing a ceramic honeycomb body according to claim 1 , wherein the removal by machining is conducted by longitudinally cutting the ceramic honeycomb body, which is rotating at a circumferential speed of 1-10 m/s, with a feeding rate of 0.1-1 mm/rev.

4. The method for producing a ceramic honeycomb body according to claim 1 , wherein said ceramic honeycomb body is a sintered body.

5. The method for producing a ceramic honeycomb body according to claim 1 , wherein a peripheral surface of the ceramic honeycomb body, from which said peripheral portion is removed by machining, is coated with a coating material to form a ceramic honeycomb structure.

6. The method for producing a ceramic honeycomb body according to claim 1 , wherein the removal of said peripheral portion by machining is conducted by

feeding said tool along said rotating ceramic honeycomb body from the first end surface toward the second end surface, to remove said peripheral portion by machining up to a position of 1 mm or more from the second end surface, stopping the feeding of said tool with an unmachined peripheral portion left on the side of the second end surface, and stopping the rotation of said ceramic honeycomb body;

releasing said ceramic honeycomb body from said lathe;

reversing the first and second end surfaces of said ceramic honeycomb body, rotatably holding said ceramic honeycomb body on the main axis of the lathe, such that its center axis is substantially in alignment with the main axis of the lathe, and rotating said ceramic honeycomb body around said main axis;

and

feeding said tool along the rotating ceramic honeycomb body from the second end surface toward the first end surface, to remove said unmachined peripheral portion by machining.

7. The method for producing a ceramic honeycomb body according to claim 1 , wherein the removal of said peripheral portion by machining is conducted by

feeding said tool along said rotating ceramic honeycomb body from the first end surface toward the second end surface, to remove said peripheral portion by machining up to a position of 1 mm or more from the second end surface, stopping the feeding of said tool with an unmachined peripheral portion left on the side of the second end surface, and causing said tool to retreat from said ceramic honeycomb body; and

feeding said tool along said rotating ceramic honeycomb body from the second end surface toward the first end surface, to remove said unmachined peripheral portion by machining.

8. The method for producing a ceramic honeycomb body according to claim 1 , wherein before the peripheral portion is removed from said ceramic honeycomb body by machining with a tool, the first and second end surfaces of said ceramic honeycomb body are chamfered.

9. The method for producing a ceramic honeycomb body according to claim 1 , wherein said abutting surface has recess.

10. The method for producing a ceramic honeycomb body according to claim 1 , wherein the area ratio of said abutting surface to a cross section of said abutting portion perpendicular to said main axis is 50-100%.

11. The method for producing a ceramic honeycomb body according to claim 10 , wherein said abutting surface has a recess.

12. The method for producing a ceramic honeycomb body according to claim 1 , wherein the area ratio of said abutting surface to a cross section of said abutting portion perpendicular to said main axis is 70-100%.

13. The method for producing a ceramic honeycomb body according to claim 12 , wherein said abutting surface has a recess.

14. The method for producing a ceramic honeycomb body according to claim 1 , wherein said abutting surface has surface roughness (maximum height Rz) of 50-400 μm.

15. The method for producing a ceramic honeycomb body according to claim 1 , wherein said abutting surface has surface roughness (maximum height Rz) of 80-350 μm.

16. The method for producing a ceramic honeycomb body according to claim 1 , wherein said abutting surface has surface roughness (maximum height Rz) of 50-400 μm.

17. The method for producing a ceramic honeycomb body according to claim 1 , wherein said abutting surface has surface roughness (maximum height Rz) of 80-350 μm.