| 摘要 |
PURPOSE:To control the discharge amount of a pump to the min. necessary flow- rate as required in each ease independently of the number of revolution of an engine during idling or traveling and control the discharge amount of the pump to the max. flow-rate corresponding to the number of revolution of the engine during operation in which the oil discharged from the pump is supplied, by using a variable displacement pump driven by the engine. CONSTITUTION:When selector valves 15, 7a, and 7b are in neutral state, a pressure control valve 17 is operated by the differential pressure generated at a throttle 3, and a part of the oil discharged from the pump flows into a head side cylinder chamber 9f, and the pump tilt angle is reduced. When the selector valve 7a is switched, the head side cylinder chamber 9f communicates to a tank 11 through a variable throttle 26. A piston 9b is shifted to the right by the pressure of the third conduit 10 and the spring force of a regulating spring 9a, and the max. pump tilt angle is formed, and the discharge amount of the pump becomes max., corresponding to the number of revolution of an engine, therefore, energy loss in an engine driven type hydraulic controller can be prevented. |
