| 摘要 |
<p>PURPOSE:To prevent the occurrence of shock during the converging period by connecting the regulator of a variable oil-pressure pump with the operating pilot pressures of each control valve and a pilot pump through a switch valve to be operated by the operating pilot pressure. CONSTITUTION:A boom control valve 4 is connected in parallel at the lowest downstream to the first variable pump P1, and an arm convergence control valve 5 is connected in tandem to the control valve 4. An arm control valve 9 is connected in parallel at the lowest downstream to the second variable pump P2, and a boom convergence control valve 11 is connected in tandem to the control valve 9. The pilot pump pressure is connected to the operating pilot pressures of each control valve through a shuttle valve and the regulators 40 and 41 of both the pumps through a switch valve to be operated by the operating pilot pressure. Shock to be encountered during the convergent period can thus be prevented by controlling the flow rate of bleed.</p> |
