| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent lowering of rotating speed of a hydraulic motor for a lifting magnet when engine speed is lowered, in regard to a hydraulic control circuit of a working machine provided with the hydraulic motor for a lifting magnet, other hydraulic actuator and a pilot circuit for pilot-operating a control valve for other hydraulic actuator. <P>SOLUTION: A third hydraulic pump P3 as an oil pressure supply source for the hydraulic motor 9 for a lifting magnet and the pilot circuit 10 is provided, and while a priority valve 13 for supplying a constant flow to the hydraulic motor 9 for lifting magnet with priority and for supplying residual flow to the pilot circuit 10 is arranged in a discharge line 12 of the third hydraulic pump 3. Furthermore, an accumulator 27 for supplying pressure oil to the pilot circuit 10 when the supply flow from the priority valve 13 to the pilot circuit 10 is short is connected to the pilot circuit 10. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
