| 摘要 |
<p>PURPOSE:To reduce the loss of energy by a method in which a combining valve to join oils of two pumps is provided and the combination of oil flows is controlled in proportion to pilot flow rates passing through the first and second orifices formed in the flow courses of the first-third ports. CONSTITUTION:A switching valve 17 and boom cylinders 18 and 19 are provided to the circuit system of the first pump 15, and a switching valve 20 and a turning motor 21 are provided to the circuit system of the second pump 16. Also, a combining valve A is provided to the first pump 15 side, the first-third ports 23-25 are formed in the valve body 22, and a spool 34 is slidably provided to the valve body 22. Each resistor consisting of the first and second detection orifices 56 and 53 is combined with the other in a bridged state. By this, control on the combination of oil flows proportional to the pilot flow is made possible, thus avoiding the combination of oil flows to excessive extent.</p> |
