| 摘要 |
PURPOSE:To manufacture inexpensively a crank shaft having a sound weld zone by keeping the joint face of the journal part of a crank pin made of cast steel horizontal and after building up, butt welding at the journal part. CONSTITUTION:The crank pin is made of cast steel making a throw part 1 in which the crank pin 1a and a crank arm 1b are unified and a part of the journal part 2 monoblock. The end face of the journal part 2 is made horizontal and built up, and adjoining built-up end faces 2a, 2a are butt welded 2b. Consequently, the cast steel faces are welded soundly and covered with built-up layers of good weldability. These are butt welded and a crank shaft of a multicylinder engine having highly reliable weld zone is obtained. As this crank shaft is made of cast steel, and welding rod that are used for ordinary structure steel can be used for building up and butt welding, the crank shaft can be manufactured inexpensively. |
