SECONDARY AIR SUPPLY STRUCTURE, METHOD FOR MANUFACTURING THE SAME, EXHAUST MANIFOLD, AND FLANGE STRUCTURE THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a simple secondary air supply structure of excellent reliability at low cost. SOLUTION: This secondary air supply structure is provided with an exhaust manifold 27 including manifold flange parts 27a comprising flat parts formed like flanges on respective opening edges of a plurality of branch pipes to be respectively connected to a plurality of exhaust ports 21, and a heat insulator 28 including heat insulator flange parts 28a comprising grooves 28b having opening parts with recessed cross sectional form formed to overlap with the flat parts of the manifold flange parts 27a for installing a heat insulator cover part onto the exhaust manifold 27. An opening part of the groove 28b is closed with the manifold flange part 27a, so that a secondary air supply passage 30 is formed of an inner circumferential wall of the groove 28b and a wall surface of the manifold flange part 27a facing it. COPYRIGHT: (C)2004,JPO