| 摘要 |
PURPOSE:To perform the safe work by limiting the workable area on the basis of the ratio between the tipping side moment varying in accordance to the stretching of the stable foot and the stable side moment while disabling the boom operation in the direction exceeding over the safety limit. CONSTITUTION:The distance (h) between the base end (b) of the boom 2 and the hoist cylinder 12 is calculated from the hoist angle of the boom 2 measured by the block 21. While the shorter one of the stretching of the outtrigger 10 measured by the block 23 is selected by the block 24. Furthermore the slew angle of the boom 2 is measured by the block 25 while the compressing force F of the hoist cylinder 12 is measured by the block 26. Then the safe side moment is calculated on the basis of the stretch of the block 24 by the block 27, while the tipping side moment is calculated by the block 28 on the basis of each value of the blocks 22, 24, 25, 26. Both moments are compared while considering the safe moment by the block 29 and the block 30 will actuate the alarm means or the operation stopping means in accordance to the compared value. |
