| 摘要 |
<p>PURPOSE:To stabilize working action when hydraulic appliances connected to a parallel hydraulic circuit in which directional control valves are coupled in parallel with hydraulic pumps are combinedly operated by hydraulic operating valves, by providing an operating signal control valve in a prescribed position. CONSTITUTION:Pumps 1, 6 are connected to hydraulic cylinders 4, 5 and those 5, 9 through directional control valves 2, 3 and those 7, 8. The directional control valves 2, 3 and those 7, 8 are coupled in parallel with te pumps 1, 6. Pilot pressure caused by an auxiliary pump 14 is appropriately distributed by the operation of hydraulic operating valves 10-12 to appropriately regulate the directional control valves 2, 3, 7, 8. An operating signal control valve 13 made of a hydraulic changeover valve is provided to control an operating signal (a) for the hydraulic operating valve 10. The control valve 13 is normally set in a position G but is shifted to a position H by an operating signal (c) for shifting the directional control valve 12 to a position C.</p> |
