Patent application number | Description | Published |
20120227391 | DEVICE AND METHOD FOR CONTROLLING HYDRAULIC PUMP OF CONSTRUCTION MACHINERY - The present invention relates to a device for controlling a hydraulic pump of construction machinery. The device has a first pump supplying working fluid through a swing control valve to a swing motor, and a second pump supplying working fluid through a work tool control valve to a work tool actuator, and includes: a first tilting angle control unit for controlling a discharge flow of the first pump by controlling a tilting angle of the first pump according to an input pump control signal; and a controller deducting a discharge pressure (P | 09-13-2012 |
20120263604 | HYDRAULIC PUMP CONTROL APPARATUS AND METHOD OF CONSTRUCTION MACHINE - 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. Accordingly, a phenomenon of stopping the engine can be prevented even if the swash plate angle sensor breaks down during a high-load operation of the engine. | 10-18-2012 |
20130255244 | HYDRAULIC SYSTEM FOR CONSTRUCTION MACHINE INCLUDING EMERGENCY CONTROL UNIT FOR ELECTRIC HYDRAULIC PUMP - 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. To this end, disclosed is the hydraulic system including the electric hydraulic pump, the electric control unit for controlling the electric hydraulic pump, and the emergency control unit, which operates when the electric control unit fails to operate, so as to temporarily control the electric hydraulic pump in accordance with to a predetermined condition, which can effectively respond to a low load work corresponding to predetermined pressure and to a high load work corresponding to higher pressure, by selectively operating the emergency control unit according to different optional conditions, based on the amount of load (low load, high load) of the working machine that is required when the electric control unit fails to operate. | 10-03-2013 |
20130312403 | HYDRAULIC SYSTEM FOR CONSTRUCTION MACHINE HAVING ELECTRONIC HYDRAULIC PUMP - 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. | 11-28-2013 |
20150017029 | PRESSURE OVERSHOOTING PREVENTION SYSTEM FOR ELECTRONIC HYDRAULIC PUMP IN HYDRAULIC SYSTEM - 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 pump. | 01-15-2015 |
20150376871 | APPARATUS AND METHOD FOR CONTROLLING OIL HYDRAULIC PUMP FOR EXCAVATOR - 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. | 12-31-2015 |
20160032945 | HYDRAULIC SYSTEM FOR CONSTRUCTION MACHINE - 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. | 02-04-2016 |
20160061236 | METHOD FOR CONTROLLING HYDRAULIC SYSTEM OF CONSTRUCTION MACHINERY - The present disclosure relates to a method for controlling a hydraulic system of construction machinery. The method for controlling the hydraulic system of construction machinery according to the present disclosure includes an engine speed prediction step, in which a variable rated engine speed, which varies within a range larger than a fixed rated engine speed and smaller than a high idle engine speed for the fixed rated engine speed and a virtual engine speed, which is to be input later, are predicted to output a virtual engine speed value predicted before an actual engine speed is input. Accordingly, when an operation load is applied, pump torque may initially have a margin, and even though an engine speed is decreased due to the operation load, it is possible to prevent an engine speed decrease phenomenon in which the engine speed becomes remarkably smaller than the rated engine speed. | 03-03-2016 |