| 摘要 |
PURPOSE:To effectively utilize an engine output, by forming the equal horsepower control range of a variable displacement oil hydraulic pump in double constitution in ranges of engine control and pump control and controlling an equal horsepower curve of the oil hydraulic pump to be used in a range of good pump efficiency. CONSTITUTION:In an engine 1, which drives pumps 2a, 2b to supply their delivery oil to actuators 3a, 3b through valves 4a, 4b, each pump 2a, 2b is controlled by servomotors 5a, 5b through control valves 6a, 6b connected with a delivery side of the pump. Here the servomotors 5a, 5b are controlled by a control unit 7 so that an output of the engine changes from the matching point in a maximum delivery capacity of the oil hydraulic pump to the increase direction of a load in an equal fuel consumption range of the engine 1 along an equal horsepower curve. While the oil hydraulic pump is equal horsepower controlled with the engine output in a fixed value in a condition exceeding an engine control range in the load increase direction. |
