| 摘要 |
A cavitation prevention system of a hydraulically driven vehicle provided with first drive pump 12, second drive and implement valve 28 supply pump 12S, combining valve 26 for combining G pressure fluids from these pumps, a movement reversing valve 21, a vehicle speed detecting pump 17 and motor 18 set and a controller 30. When the operator switches 34 the transmission between forward and rearward drive, the controller reverses switching valve 22 and thus the reversing valve to reverse fluid supply to the motor. If the vehicle is moving its inertia causes the motor 13 to continue rotating in its original direction tending to reduce pressure in forward circuit 41F, causing cavitation. If the vehicle speed is greater or equal to a set value the controller closes B combining valve 26 sending second pump fluid via unload valve 55 to pressurise the return 43 and reduce cavitation. |
