| 摘要 |
PROBLEM TO BE SOLVED: To enhance flexibility by stabilizing motor capacity to automatically control, reducing load of an operator at stopping operation or the like, and extending an application range. SOLUTION: In this control device, a center bypass port 8A is disposed to a pressure control valve 8 of a counter balance valve 6, and load pressure in a hydraulic motor 3 is supplied by the center bypass port 8A from pipe line parts 4A1 and 4B1 through a pilot line 27 to a pilot port 15B of a capacity control valve 11. A shuttle valve 9 is provided between pipe line parts 4A2 and 4B2 disposed between the hydraulic motor 3 and the counter balance valve 6, and pressure oil at a high pressure side selected by the shuttle valve 9 is supplied via a high pressure pipe line 28 and the capacity control valve 11 to a servo actuator 10, thereby changing a pressurized area to a pilot pressure of the capacity control valve 11 by a large capacity position (a) and a small capacity position (b).
|
