| 摘要 |
PROBLEM TO BE SOLVED: To improve the following property of a second hydraulic actuator when reducing the amount of operation of a first operation means in the state that a second operation means and the first operation means are each operated in one direction. SOLUTION: An operation control means 60 has a piston member 61, and a control spring member 62. With the piston member 61 degenerated, it allows one-direction movement of a bucket spool 210 of a bucket operation valve 20 up to a position where a bucket branch supply passage 30B is opened. With the piston member 61 arranged at an advance position, it abuts on the bucket spool 210 to prevent one-direction movement thereof up to a position where the bucket branch supply passage 30B is opened. COPYRIGHT: (C)2009,JPO&INPIT |
