Honeycomb core for carrying catalyst and catalytic converter
A honeycomb core for carrying a catalyst includes a flat metal foil and a corrugated metal foil, which are layered. The corrugated foil is configured by repeating a concavo-convex shaped part including a first top surface that is in contact with one of the flat foils, a second top surface that is in contact with another flat foil and is disposed at a position where the second top surface avoids the first top surface, and an inclined leg surface that has one end connected to the first top surface through a first bent part and another end connected to the second top surface through a second bent part, and extends in a direction inclined with respect to the first top surface and the second top surface, and has an offset part having different wave phases between front and rear in an axial direction of the honeycomb core.
1. A honeycomb core for carrying a catalyst, comprising a flat metal foil and a corrugated metal foil, the flat metal foil and the corrugated metal foil being layered, wherein
the corrugated foil is configured by repeating a concavo-convex shaped part including a first top surface that is in contact with one of the flat foils adjacent in a layering direction, a second top surface that is in contact with another flat foil adjacent in the layering direction and is disposed at a position where the second top surface avoids the first top surface as viewed in the layering direction, and an inclined leg surface that has one end connected to the first top surface through a first bent part and another end connected to the second top surface through a second bent part, and extends in a direction inclined with respect to the first top surface and the second top surface, and has an offset part having different wave phases between front and rear in an axial direction of the honeycomb core,
the first bent part and the second bent part each have a R shape,
a radius of curvature R 1 of an inner edge of the first bent part and a radius of curvature R 2 of an inner edge of the second bent part satisfy the following conditional expressions (1) and (2), respectively, and
a separation distance h in the layering direction between the first top surface and the second top surface and a separation distance S between a pair of the inclined leg surfaces connected to the first top surface through the first bent parts satisfy the following conditional expression (3):
0.02(mm)≤R1≤2.0(mm) (1),
0.02(mm)≤R2≤2.0(mm) (2), and
1.5≤ S/h≤ 10 (3).
2. The honeycomb core for carrying a catalyst according to claim 1 , wherein a first protrusion extends from both ends in the axial direction of the first bent part toward an exhaust gas flow channel that is disposed between the first top surface and the other flat foil as viewed in the axial direction, and a second protrusion extends from both ends in the axial direction of the second bent part toward an exhaust gas flow channel that is disposed between the second top surface and the one flat foil as viewed in the axial direction.
3. The honeycomb core for carrying a catalyst according to claim 2 , wherein a protrusion length B 1 of the first protrusion and a protrusion length B 2 of the second protrusion satisfy the following conditional expressions (4) and (5), respectively:
2(μm)≤B1≤45(μm) (4), and
2(μm)≤B2≤45(μm) (5).
4. The honeycomb core for carrying a catalyst according to claim 1 , wherein an inclination α of the inclined leg surface with respect to the layering direction satisfies the following conditional expression (6):
0.5°≤α15° (6).
5. The honeycomb core for carrying a catalyst according to claim 1 , wherein a length L of the concavo-convex shaped part in the axial direction satisfies the following conditional expression (7):
0.5(mm)≤L≤20(mm) (7).
6. The honeycomb core for carrying a catalyst according to claim 1 , wherein the S is 0.5 (mm) or more and 10 (mm) or less, and the flat foil and the corrugated foil have a thickness of 5 (μm) or more and 100 (μm) or less.
7. The honeycomb core for carrying a catalyst according to claim 1 , wherein the concavo-convex shaped parts are arranged in a zigzag pattern in the axial direction.
8. A catalytic converter comprising:
the honeycomb core for carrying a catalyst according to claim 1 ;
a catalyst carried on the honeycomb core for carrying a catalyst; and
an outer metal cylinder surrounding an outer circumference surface of the honeycomb core for carrying a catalyst.
9. The honeycomb core for carrying a catalyst according to claim 2 , wherein an inclination α of the inclined leg surface with respect to the layering direction satisfies the following conditional expression (6):
0.5°≤α≤15° (6).
10. The honeycomb core for carrying a catalyst according to claim 3 , wherein an inclination α of the inclined leg surface with respect to the layering direction satisfies the following conditional expression (6):
0.5°≤α≤15° (6).
11. The honeycomb core for carrying a catalyst according to claim 2 , wherein a length L of the concavo-convex shaped part in the axial direction satisfies the following conditional expression (7):
0.5(mm)≤L≤20(mm) (7).
12. The honeycomb core for carrying a catalyst according to claim 3 , wherein a length L of the concavo-convex shaped part in the axial direction satisfies the following conditional expression (7):
0.5(mm)≤L≤20(mm) (7).
13. The honeycomb core for carrying a catalyst according to claim 4 , wherein a length L of the concavo-convex shaped part in the axial direction satisfies the following conditional expression (7):
0.5(mm)≤L≤20(mm) (7).
14. The honeycomb core for carrying a catalyst according to claim 9 , wherein a length L of the concavo-convex shaped part in the axial direction satisfies the following conditional expression (7):
0.5(mm)≤L≤20(mm) (7).
15. The honeycomb core for carrying a catalyst according to claim 10 , wherein a length L of the concavo-convex shaped part in the axial direction satisfies the following conditional expression (7):
0.5(mm)≤L≤20(mm) (7).
16. The honeycomb core for carrying a catalyst according to claim 2 , wherein the S is 0.5 (mm) or more and 10 (mm) or less, and the flat foil and the corrugated foil have a thickness of 5 (μm) or more and 100 (μm) or less.
17. The honeycomb core for carrying a catalyst according to claim 3 , wherein the S is 0.5 (mm) or more and 10 (mm) or less, and the flat foil and the corrugated foil have a thickness of 5 (μm) or more and 100 (μm) or less.
18. The honeycomb core for carrying a catalyst according to claim 4 , wherein the S is 0.5 (mm) or more and 10 (mm) or less, and the flat foil and the corrugated foil have a thickness of 5 (μm) or more and 100 (μm) or less.
19. The honeycomb core for carrying a catalyst according to claim 5 , wherein the S is 0.5 (mm) or more and 10 (mm) or less, and the flat foil and the corrugated foil have a thickness of 5 (μm) or more and 100 (μm) or less.
20. The honeycomb core for carrying a catalyst according to claim 9 , wherein the S is 0.5 (mm) or more and 10 (mm) or less, and the flat foil and the corrugated foil have a thickness of 5 (μm) or more and 100 (μm) or less.