Patent ID: 6500393
Filing Date: 2002-12-31
Classification: B23K,F01N,Y10T

Abstract:
A metal support for an exhaust gas purifying catalyst, said metal support comprising a cylindrical honeycomb structure including a spirally wound strip metal flat sheet and a spirally wound strip metal corrugated sheet overlapped on said strip metal flat sheet, wherein, for each turn, a first circumferential surface of said metal flat sheet contacts and is welded, using a laser beam, to said metal corrugated sheet at a plurality of axially arranged welding positions corresponding to mutual contact portions where said first circumferential surface said metal flat sheet contacts said metal corrugated sheet; andsaid metal support further comprising cylindrical casing within which said honeycomb structure is mounted, wherein said plurality of welding positions are arranged to satisfy the following condition: a first condition wherein a maximum value L1 of distances each between adjacent ones of said plurality of welding positions satisfies at least one of relationships given by L1&lE;D/2 and L1&lE;L/2 where L is the axial length of said honeycomb structure and D is the diameter of said honeycomb structure, a second condition wherein a distance L2 between an outermost one of said plurality of said welding positions in the axial direction of said honeycomb structure and an outer end surface of said honeycomb structure satisfies at least one of relationships given by L2&lE;D/20 and L2&lE;L/10, and a third condition of L2>d/2, wherein d is the diameter of the laser beam used to perform the welding operation.