| 摘要 |
PURPOSE:To control the pressure-flow characteristic of a pump by oil temperature so as to enable the full use of engine (power source) horsepower. CONSTITUTION:The oil temperature of a variable displacement hydraulic pump 2 connected directly to an engine 1 is detected by a temperature sensor 4 provided at an operating oil tank 3 or the like. This signal is received as a temperature current 5 by a pump controller 6 for operation. According to this operation result as a torque control current 7, a current is changed to control the flow of the variable displacement hydraulic pump 2 through a torque control valve 8. The decrease of pump flow caused by oil temperature rise is thereby prevented to enable the effective use of engine horsepower. |
