| 摘要 |
<p>PURPOSE:To smooth compound action by providing a switching valve, controlling direction switching valves, on a circuit driving plural actuators with plural hydraulic pumps, and neutralizing one side of the direction switching valves at the time of plural actions. CONSTITUTION:Plural actuators (arm and boom cylinders 2a and 2b) are operated with first and second pilot valves 24 and 28 with plural hydraulic pumps 1a and 1b. The first pilot valve 24 is connected to the boom cylinder 2b via direction switching valves 10 and 16, and the second pilot valve 28 is linked to an arm cylinder 2a via switching valves 7 and 13. Moreover, a switching valve 45 is installed which forcedly neutralized one side of the switching valves 7 and 13 when the first and second pilot valves are operated concurrently. This can smooth compound action without reducing a speed at the time of the single action of an arm.</p> |
