WELDING PART PROTECTION STRUCTURE OF BOSS FOR EXPANSION CYLINDER CONNECTION IN EXPANSION BOOM

摘要

PROBLEM TO BE SOLVED: To reduce stress (kneading operation) applied on a boss welding part in a crane working state even when the thickness of a boom side plate to which the boss for expansion cylinder connection is relatively small.;SOLUTION: In an expansion boom 1 having expansion cylinder connection bosses welded to the opposed positions of right and left boom side plates 14 in a boom cylinder 13, in a position near the boom expansion side in the boss welding part 3 of each boom side plate 14, a slit 5 is vertically formed to absorb deformation stress applied on the boom side plate near the boom reduced side of the boss welding part 3 when the boom side plate 14 is pressed to the boom reduced side with respect to the boss welding part 3. Thus, the stress applied on the boss welding part 3 during crane working is absorbed by the slit 5 part.;COPYRIGHT: (C)2013,JPO&INPIT