Abstract: The present disclosure relates to a hydraulic system for a construction machine, and more particularly, to a hydraulic system for a construction machine including a plurality of actuators, in which each of the actuators includes a pump/motor, is operated under a control of a corresponding pump/motor, and stores working oil in an accumulator or receives the working oil supplemented from the accumulator in accordance with a difference between a flow rate entering the actuator and a flow rate discharged from the actuator.

Abstract: An exemplary embodiment of the present specification relates to an apparatus for controlling a hydraulic pump for an excavator with respect to a change of an operation mode, the apparatus including: an operating unit configured to generate an operation signal according to an operation of an operator, and including a joystick or a pedal; an oil flow supplying unit configured to supply oil to actuators, in order to drive a plurality of actuators corresponding to the operation signal, and including a plurality of pumps and a plurality of logic valves; and a control unit configured to control the oil flow supplying unit by using a priority algorithm for each operation considering a use frequency and a load of the actuator with respect to a change of a predetermined operation mode according to the operation signal.

Abstract: In a hydraulic pump control apparatus and method of a construction machine, the control apparatus includes a pump control unit for controlling discharge pressure of a pump driven by an engine. The control unit includes: a pressure setting value calculating unit which calculates a pressure setting value based on an engine output torque estimating value or an engine RPM; and a breakdown treating unit selects one of the pressure setting value and a pressure command value according to a breakdown of the swash plate angle sensor to output the selected value. Since the pump is controlled according to a pressure setting value calculated based on the engine output torque estimating value, the absorption torque value of the pump does not exceed the maximum torque value of the engine even when the swash plate angle sensor breaks down, and related engine stoppage is prevented even during a high-load operation.

Abstract: The present invention relates to a device for controlling a hydraulic pump of construction machinery.

Abstract: The present disclosure relates to a pressure overshooting prevention system for an electronic hydraulic pump in a hydraulic system, in which a flow rate command is added (+), a discharge flow rate is subtracted (?), a displacement flow rate (Delta Q) is calculated, a first pressure command corresponding to the displacement flow rate (Delta Q) is generated, a working fluid pressure value corresponding to the discharge flow rate is generated, a limit pressure command is generated to limit an increasing gradient of the working fluid pressure value, a stall is determined based on a first rate of change of the flow rate command, and a second rate of change of the discharge flow rate, and the limit pressure command is set to a second pressure command when the stall is determined, and a small value of the first pressure command and the second pressure command is selected as a final pressure command so as to control an electronic proportional control valve, thereby reducing overshooting of the electronic hydraulic pu

Abstract: The present disclosure relates to a hydraulic system for a construction machine having an electronic hydraulic pump, and more particularly, to a hydraulic system which temporarily drives the construction machine when an operation of an electronic control unit controlling an electronic hydraulic pump is abnormal, particularly, when the electronic control unit is not able to perform a control because an operative amount of a joystick input to the electronic control unit is not normally transmitted to the electronic control unit.

Abstract: The present disclosure relates to a hydraulic system for a construction machine which uses an electric hydraulic pump, and more particularly, to a hydraulic system including an emergency control unit for temporarily driving the construction machine when an electronic control unit controlling the electric hydraulic pumps fails to operate.

Abstract: Disclosed are a hydraulic pump control apparatus and a hydraulic pump control method of a construction machine. The hydraulic pump control apparatus includes a pump control unit for controlling a discharge pressure of a hydraulic pump driven by an engine. The pump control unit includes: a pressure setting value calculating unit configured to calculate a pressure setting value based on an engine output torque estimating value or an engine RPM; and a breakdown treating unit configured to select one of the pressure setting value and a pressure command value according to a breakdown of the swash plate angle sensor to output the selected value. Since the pump is controlled according to a pressure setting value obtained by calculating the pressure setting value based on the engine output torque estimating value, the absorption torque value of the pump does not exceed the maximum torque value of the engine even when the swash plate angle sensor breaks down.

Abstract: The present invention relates to a device for controlling a hydraulic pump of construction machinery.