| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of crack and buckling in a welded part where exhaust single pipes of an exhaust manifold are integrally collected. SOLUTION: This exhaust manifold EM is constituted by forming downstream ends 12a to 15a of a plurality of exhaust single pipes 12 to 15 extending from a plurality of exhaust ports of a multi-cylinder engine so as to have fan-shaped cross sections, combining the downstream ends 12a to 15a of the exhaust single pipes 12 to 15 in a circular shape, and integrating them by welding. By performing padding on an inner face of a part equivalent to a main point p of the fan-shaped cross section of each exhaust single pipe 12 to 15 by welding beads 20 to provide a rigidity increased part, it is possible to increase the rigidity of the part and prevent the occurrence of crack and buckling due to heat of exhaust gas. Instead of performing padding in the part equivalent to the main point p of the fan-shaped cross section by welding beads 20, a wall thickness of a material in the part may be increased. |
