Honeycomb unit for exhaust emission control

摘要

A metal honeycomb structure includes planar and corrugated sheets brazed together at first and second joining portions made of brazing materials applied to the corrugated sheet. The first and second joining portions are located proximate exhaust inlet and outlet of the honeycomb structure. The honeycomb further includes a joining strip joined to a metal outer tube. The joining strip is made of a brazing material applied to an inner wall of the metal outer tube. The second joining portion overlaps the joining strip and has a brazing length larger than a brazing length of the first joining portion which does not overlap the joining strip.

主权项

1. A honeycomb unit for exhaust emission control, comprising:
a metal outer tube; and a metal honeycomb structure pressed into and joined to the metal outer tube, the metal honeycomb structure including: a joining strip joined to the metal outer tube; a planar sheet; a corrugated sheet placed on the planar sheet, the corrugated sheet and the planar sheet being wound together, the corrugated sheet including an outer surface having crests and an inner surface having crests; first and second joining portions brazing the planar sheet and the corrugated sheet together; the first joining portion and the second joining portion being located proximate opposing ends of the metal honeycomb structure; the first joining portion including first joining sections formed of brazing materials applied to the crests of the outer surface of the corrugated sheet and second joining sections formed of brazing materials applied to the crests of the inner surface of the corrugated sheet; the second joining portion including first joining sections formed of brazing materials applied to the crests of the outer surface of the corrugated sheet and second joining sections formed of brazing materials applied to the crests of the inner surface of the corrugated sheet; the first joining sections of the first joining portion and the first joining sections of the second joining portion being offset from the second joining sections of the first joining portion and the second joining sections of the second joining portion in directions parallel to an axis of the metal honeycomb structure; the second joining portion and the joining strip overlapping, the first joining portion and the joining strip not overlapping; the first joining portion having a first brazing length along the axis of the metal honeycomb structure; the second joining portion having a second brazing length along the axis of the metal honeycomb structure; and the second brazing length of the second joining portion being larger than the first brazing length of the first joining portion; wherein one of the opposing ends of the metal honeycomb structure defines an exhaust outlet of the honeycomb structure, and the joining strip is disposed only on a side of the exhaust outlet.