| 摘要 |
<P>PROBLEM TO BE SOLVED: To easily provide a flow rate required by a boom control circuit, by making the boom control circuit independent. <P>SOLUTION: The boom control circuit 45 for controlling a working fluid to a boom cylinder 8bmc is independently and separately arranged to a hydraulic pressure actuator control circuit 25 for controlling the working fluid to traveling motors 2trL and 2trR, a stick cylinder 8stc and a bucket cylinder 8bkc. The boom control circuit 45 has a boom pump 48. An energy regenerative motor 86 is arranged in one return passage 56 for passing a return fluid from the boom cylinder 8bmc. A motor-driven generator 87 for a boom is connected to this energy regenerative motor 86. The boom pump 48 is connected to this motor-driven generator 87 for the boom via a clutch 88. <P>COPYRIGHT: (C)2007,JPO&INPIT |
