| 摘要 |
PURPOSE:To prevent the deterioration of noise and exhaust by decreasing the pump suction torque from the preset value in response to the deceleration of the rotating speed in limiting the pump suction torque of variable-discharge pumps driven by an engine to the preset value to control the discharge of the pumps. CONSTITUTION:Inclination angles of swash plates are changed by servo cylinders 4 and 5 of variable-displacement hydraulic pumps 1 and 2 driven by an engine 3 to change the discharge flow, the servo cylinders 4 and 5 are driven by the pressure oil from a control pump 10. The discharge oil from the pumps 1 and 2 is fed to a hydraulic motor driving a working machine and a traveling caterpil lar band or the like via operating valves 6 and 7. In this case, the servo cylinders 4 and 5 are controlled to make the synthetic suction torque of the pumps 1 and 2 constant by the action of a TVC valve 20, the pump suction torque is decreased from the preset value in response to the deceleration of the engine rotating speed, thus the quick reduction of the engine rotation is suppressed. |
