| 摘要 |
<P>PROBLEM TO BE SOLVED: To substantially equally share a load acting on first and second hydraulic motors when lifting and lowering an object to be lifted and lowered without complicating a hydraulic circuit. <P>SOLUTION: The hydraulic circuit includes: a common supply and discharge passage for supplying pressure liquids discharged from a hydraulic pump to first and second hydraulic motor sides; first and second branch passages branched from the common supply and discharge passage, respectively, the first branch passage connected to the first hydraulic motor, the second branch passage connected to the second hydraulic motor; a counter balance mechanism provided at the common supply and discharge passage which works as the supply side during hoisting drive; and throttle parts provided on supply and discharge paths of the first branch passage, respectively. The distance of the passage from the hydraulic pump to the first hydraulic motor is shorter than the distance of the passage from the hydraulic pump to the second hydraulic motor. The throttle part has an inner diameter reducing or substantially eliminating a difference between first split flow passage resistance by the first branch passage and the first hydraulic motor and second split flow passage resistance by the second branch passage and the second hydraulic motor. <P>COPYRIGHT: (C)2013,JPO&INPIT |
