| 摘要 |
PURPOSE:To prevent early burning by performing build-up welding of highly corrosion-resistant alloy at the portion on top of the piston crown subject to burning. CONSTITUTION:Built-up welding 14 of highly corrosion-resistant alloy is performed on top 13 of the piston crown 12 of piston 11. The welding 14 is performed at the portion easily subject to burning from immediately below the fuel valve along the fuel injecting direction in crescent within the range of about 90 deg.. Consequently, the durability of the piston crown 12 can be improved economically. When immersing the lower section including the piston ring shelf section 17 into cooling oil tank 18 to suppress temperature rise during repair welding, entire repairment of piston ring shelf 17, multi-joint face, bolt hole, etc. is not required. |
