| 摘要 |
<p>This invention relates to a hydraulic driving unit for a working machine, which is provided with hydraulic pump (1); at least one hydraulic actuator (3) driven by hydraulic fluid discharged from the hydraulic pump; a flow rate control valve (4) driven according to the degree of operation of an operating means (4a) to control the flow of the hydraulic fluid fed from the hydraulic pump to the actuator; detection pipings (7a, 7b) for picking up the load pressure in the actuator; and a pressure compensating means (2 or 5) connected to the detection pipings and keeping the difference between the pressure on the upstream side of the flow rate control valve and the load pressure of the actuator on a specified level. This hydraulic driving unit is further equipped with a pressure limiting means (20) disposed with respect to the detection pipings (7a, 7b) to limit the load pressure of the actuator picked up by the detection pipings below a value to be determined according to the degree of operation of the operating means (4a).</p> |
