摘要 |
PURPOSE:To improve airtightness and reliability by forming a gap part on a butt-joint outside surface beforehand and melting and fusing, by the hot wind in non-contact type, the projected edge of a flange part which projects outside in the state closely fitted by a pressed pressure. CONSTITUTION:Flange parts 11-1 and 11-2 which project outside are formed on the butt-joint parts of silencer bodies 7-1 and 7-2, and each thickness of the flange parts 11-1 and 11-2 is made smaller than that of silencer parts 7-2a and 7-2b, and a gap is formed between the flange parts 11-1 and 11-2, and the flange parts are pressed and closely attached by a pressing jig 15, and the projected edges of the flange parts are molten and fused over the whole periphery by the hot wind in non-contact type. Therefore, a pressing force always acts onto the inside butt-joint surface of a coolant flow passage, and the seal performance of the inside butt-joint part is improved by said pressing force, and thus airtightness and reliability can be improved. |