| 摘要 |
<P>PROBLEM TO BE SOLVED: To synchronize the revolving time of a revolving upper structure and extent of the boom elevation during the revolving time in a hydraulic shovel which employs a hydraulic circuit comprising an independent boom circuit. <P>SOLUTION: On a hydraulic shovel, a hydraulic cylinder moves a boom by use of the oil delivered from a first hydraulic pump. A first hydraulic circuit connects the first hydraulic pump and the hydraulic cylinder, forming a closed circuit between the first hydraulic pump and the hydraulic cylinder. A hydraulic motor turns a revolving upper structure by use of the oil delivered from a second hydraulic pump. The second hydraulic circuit is formed independently from the first hydraulic circuit, connecting the second hydraulic pump and the hydraulic motor. A motor-hydraulic-pressure-reducing part reduces the drive hydraulic pressure of the hydraulic motor when designated conditions are met. The designated conditions are that an operation of a boom-control component for raising the boom and an operation of a revolving-operation component for turning the revolving upper structure are performed in parallel, and control input of the boom-control component is equal to or more than a threshold value. <P>COPYRIGHT: (C)2013,JPO&INPIT |
