| 摘要 |
<p>PURPOSE:To increase the rotary operability and the safety of rotary movement at a narrow space in a construction site, by controlling the rotary speed or others of a hydraulic shovel on the base of a specified boom angle and a retracting angle of the arm previously stored in the memory of a controller. CONSTITUTION:The raised angle (a) of boom where the boom 8 reaches almost the highest position and the retracted angle (b) of arm where the arm 9 is retracted to the almost maximum position are stored in advance in the memory of a controller 6. The raised angle of boom and the retracted angle of arm are detected by a posture detector respectively. The detected angle is compared with the angle previously stored in the memory and a changeover-instruction signal is output to a changeover valve through the controller 6. While the boom 8 is kept at the almost highest position and the arm 9 is kept at the almost maximum retracted position, or while the rotary radius is kept minimum, the rotary speed is automatically reduced to a slow speed. In this way, the boom and the arm can be carefully and safely turned.</p> |
