| 摘要 |
PURPOSE:To properly weld even a part of a metallic ring positioned near an exhaust value and prevent the deformation of the ring. CONSTITUTION:For a metallic substrate 20 having a combustion chamber hole 21 drilled at a position faced to a combustion chamber, a metallic ring 40 is welded to the hole 21 all around with substantial continuity. In this case, the welding work is undertaken so that the internal area of the ring 40 becomes almost equal to the external area about a center relative to the welded section 41 of the ring 40 over a specific range theta a thereof at a position near an exhaust valve. |
