| 摘要 |
<p>PURPOSE:To improve the salty at the time of revolution by automatically drawing a counterweight protruded behind a revolving superstructure when it is revolved at the time of the excavation work. CONSTITUTION:The secondary pressure for operation is inputted to the protrusion command side port 29 of a balance selector valve 28 provided on the hydraulic circuit of a balance cylinder 12 via a pilot selector valve 31 to improve the balance of a hydraulic shovel. The pilot pressures from revolving operation circuits 39, 40 can be inputted to a withdrawal command side port 30 to selectively operate the balance selector valve 28. The pilot selector valve 31 is provided on a pilot pipe communicated with the protrusion command side port 29, the signal output applied to the withdrawal command side port 30 is set to have preference to the signal output applied to the protrusion command side port 29, a protruded counterweight is automatically drawn, a collision accident with an obstacle at the time of revolution is prevented, and safety is secured.</p> |
