JOINT STRUCTURE OF CYLINDRICAL BODY AND PINCHING FIXING BASE PLATE

摘要

PROBLEM TO BE SOLVED: To obtain sufficient welding length even when the overlapping site of a base plate joined with a cylindrical body is shortened, and to sufficiently disperse even stress. SOLUTION: An arm 24 in which a boom 22, an arm cylinder 25 and an operating-tool cylinder 27 are connected at a base section and an operating tool 26 is supported pivotally at a front end is formed of the cylindrical body 31 reaching up to the front end from approximately the base section and a pair of the left-right base plates 32 welded in a pinching manner on the base- section side of the cylindrical body 31. Scooped-out sections 33 in which the front end sides are opened are formed at the cylindrical-body overlapping sites P of the base plates 32.