| 摘要 |
PROBLEM TO BE SOLVED: To facilitate the work, by constituting a cover for covering the frontage of the upper face of a housing part so as to automatically open/close the cover in accordance with the change of the posture of an attaching/detaching device from the containing posture to the attaching/detaching posture. SOLUTION: When an attaching/detaching device 6 for a counterweight is under the housing posture in which it is housed in a recessed groove 11, the cover 12 is urged to keep the closed posture that the frontage of the upper face of the recessed groove 11 is always closed by a spring equipped in a hinge 13. When the posture of the device 6 is changed to the attaching/detaching posture to attach or detach the counterweight 5, the device 6 projects upward higher than the upper face 3b of the upper slewing body and contacts the cover 12 from the lower side to push up the cover 12 and open the opening of the upper face of the recessed groove 11. In this way, as the cover can be automatically opened or closed, the work can be facilitated. |
