| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic pump control device offering simple and inexpensive construction permitting easy change into mechanical control even when an electric system is in trouble. SOLUTION: The hydraulic pump control device comprises a first pilot line 24 and a second pilot line 25 formed and a shuttle valve 26 provided therebetween. The shuttle valve 26 selects higher one of a pressure P1 in the first pilot line 24 and a pressure P2 in the second pilot line 25. The output of the shuttle valve 26 is guided to a flow control cylinder 28. The pressure P2 in the second pilot line 25 is guided to a horse power control cylinder 29. The pressure P1 is used as a pilot pressure in a normal condition, and the pressure P2 is used as the pilot pressure when the electric system is malfunctioned. |
