| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a hydraulic circuit capable of driving a hydraulic cylinder by regenerating hydraulic fluid for operating the hydraulic cylinder and saving energy by a simple configuration. <P>SOLUTION: This hydraulic device is provided with a hydraulic pump 31, an operation switching valve 32 arranged between a boom cylinder 22 and the hydraulic pump 31, an oil pressure adjusting mechanism 37 for adjusting difference between pressure on a discharge port side of the hydraulic pump 31 and pressure on a secondary side of the operation switching valve 32 to a predetermined value, and a regenerative pipe 36 for supplying the hydraulic fluid from an oil discharge port of the boom cylinder 22 into the hydraulic pump 31. A cylinder bottom chamber side port 32c, a cylinder rod chamber side port 32d, and a load pressure taking-out port 32f are provided on the secondary side of the operation switching valve 32, and a pump port 32a, a regenerative port 32b, and a drain port 32e are provided on a primary side of the operation switching valve 32. When switching a cylinder contraction position, surplus flow on a rod side is discharged from the drain port 32e. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
