| 摘要 |
PURPOSE:To permit the generation of optimum alarm by a method in which forces to be applied to an oil-pressure shovel are calculated from the detected values of displacement of a boom, an arm, and a bucket and the drive pressure of the boom cylinder and then compared with a falling limit value. CONSTITUTION:The angular signals Ealpha1, Ebeta1, and Egamma1 of a boom 1, an arm 2, and a bucket 3 constituting the front mechanism T of an upper rotator S are detected, and pressure signals Epb and Epr on the bottom and rod sides of the boom cylinder 4 are detected. An arithmetical unit 7 is made up of an unload moment arithmetic section 9, a front moment arithmetic section 10, a memory 15, and a comparator 16. An alarm device 8 is operated. The signals Ealpha1-Egamma1 and Epb are each put in the arithmetic sections 9 and 10 to calculate a moment to act on the supporting point (not illustrated) where the falling can most take place and the moment is compared with the moment by the weight of the shovel body, previously stored in the memory 15, and an alarm is generated. |
