| 摘要 |
PROBLEM TO BE SOLVED: To mitigate stress at junction between a longitudinal plate and a rear side connection plate (lateral plate) without increasing height of the rear side connection plate while preventing the size of an aperture for fitting a revolving motor, piping, etc. from being decreased.SOLUTION: A longitudinal plate projection 21 extending upward higher than the upper end of a rear side connection plate 16 is provided on a longitudinal plate 12. The upper face of the rear end of a doubling plate 12a and an upper face 16a of the rear side connection plate 16 are butted to each other so that the faces are flush with each other. A weld between the side face of the longitudinal plate 12 and the upper face of the rear end of the doubling plate 12a and a weld between a rear end face 12b of the longitudinal plate 12 and the upper face 16a of the rear side connection plate 16 are connected by a continuous weld 30 without a step.SELECTED DRAWING: Figure 5 |
