| 摘要 |
<p>PURPOSE:To prevent temperature rise of operating oil by increasing the discharge rate of a variable pressure oil on the side where an oil cooler is connected when an actuator on the side where a cooler is not connected in the return passage is actuated. CONSTITUTION:A cam 15 is provided for a selector valve 13 in a directional selector valve group 4 on the side where an oil cooler is not connected to the return passage. The cam is engaged to a rod 7 of a variable pressure oil pump 1 through a rod 16, and when an actuator 12 is activated the discharge rate of the variable pressure oil pump 1 connected to the side where an oil cooler 11 is connected, is increased. By this arrangement, the operating oil is prevented from raising its temperature excessively because the operating oil is cooled by the cooler 11.</p> |
