| 摘要 |
<p>An improvement in a closed center-load sensing system capable of varying a discharge volume easily and highly accurately. For this purpose, the load sensing system comprises: a power source (1) having a rotary speed indicator; a variable volume hydraulic pump (2) driven by the power source; actuators (3, 4) driven by pressure oil discharged from the variable volume hydraulic pump; change-over valves (7, 8) for controlling the flow of this pressure oil; an indicator (31) for setting a rotary speed of the power source in the load sensing system in which the difference between the pump pressure and the load pressure of the actuators is held at a predetermined level, and, when this difference is changed, a flow rate of the oil discharged from the variable volume hydraulic pump is changed; a controller (33) for calculating and outputting the rotary speed of the power source in response to a command signal from the indicator; and an electronic proportional control governor (32) for controlling the rotary speed of the power source in response to a command signal from the controller; whereby the aforesaid difference in pressure is set.</p> |
