Abstract:
본 발명에 따른 건설기계의 유압펌프 제어장치는 선회제어밸브(31)를 통해 선회모터(30)에 작동유를 공급하는 제 1 펌프(10)와, 작업기 제어밸브(41)를 통해 작업기 액츄에이터(40)에 작동유를 공급하는 제 2 펌프(20)를 포함하는 건설기계의 유압펌프를 제어하기 위한 것으로서, 입력되는 펌프제어신호에 따라 상기 제 1 펌프(10)의 사판각을 조절하여 상기 제 1 펌프(10)의 토출유량을 조절하는 제 1 사판각 조절유닛(12); 및 상기 제 1 펌프(10)의 토출압력(P1)으로부터 상기 제 2 펌프(20)의 토출압력(P2)을 차감하여 펌프차압(P1-P2)을 산출하고, 상기 산출된 펌프차압(P1-P2)을 기준차압과 비교하여 상기 기준차압보다 크면, 상기 제 1 펌프(10)의 토출압력(P1)이 선회 릴리프 압력 보다 작거나 같은 제 1 기준압력 이하가 되도록 상기 제 1 사판각 조절유닛(12)에 상기 펌프제어신호를 출력하는 제어부(60)를 포함한다.
Abstract:
The hydraulic pump control device for construction machinery according to the present invention comprises: a first swash-plate-angle adjusting unit (12) which is for controlling hydraulic pumps in construction machinery comprising a first pump (10) for supplying operating fluid via a swivel control valve (31) to a swivel motor (30) and a second pump (20) for supplying operating fluid via a working-unit control valve (41) to a working-unit actuator (40), and which adjusts the swash plate angle of the first pump (10) and thereby adjusts the volume of fluid discharged from the first pump (10) in accordance with an input pump control signal; and a controller (60) which subtracts the discharge pressure (P2) of the second pump (20) from the discharge pressure (P1) of the first pump (10) and thereby calculates the pump pressure difference (P1-P2), and which compares the calculated pump pressure difference (P1-P2) with a reference pressure difference and, if the pump pressure difference is larger than the reference pressure difference, outputs a pump control signal to the first swash-plate-angle adjusting unit (12) such that the discharge pressure (P1) of the first pump (10) becomes either smaller than a swivel relief pressure or falls below the said first reference pressure.
Abstract:
A zero turn mower vehicle (10) includes left and right hydrostatic transmissions (11a, 11b) driving wheels (15a, 15b). The transmissions (11a, 11b) each include a swashplate type axial piston hydraulic pump (17) having a swashplate (22). A system (12) and method controls each pump (17). A controller (31) receives input signals and provides output signals to electric motors (33a, 33b) to control each swashplate (22). Operator interface input devices (30a, 30b) provide inputs to controller (31). Angle sensors (35a, 35b) provide additional inputs to controller (31). Displacement amplifiers (36a, 36b) amplify displacement of each swashplate (22), and torque amplifiers (34a, 34b) amplify torque of electric motors (33a, 33b).
Abstract:
The invention relates to a hydraulic assembly comprising a variable electric motor and a hydrostatic variable displacement pump which can be coupled thereto and the pivoting angle of which can be adjusted by means of a hydromechanical adjustment device, the pivoting angle being detectible by means of a pivoting angle sensor and a working pressure of the variable displacement pump being detectible by means of a pressure sensor. A speed of the electric motor can be varied depending on the pivoting angle sensor and the pressure sensor.
Abstract:
A fuel injection control device (an electronic governor (12) and a controller (13)) for an engine (1) is capable of controlling the governor region to an isochronus characteristic. A working machine controller (18) receives a delivery pressure signal (P) and controls a regulator (16) in such a manner that when the delivery pressure of a hydraulic pump exceeds a predetermined pressure (P1), the displacement volume of the hydraulic pump does not exceed a value determined by a preset pump absorption torque curve (20) and when the delivery pressure of the hydraulic pump (2) is not more than a predetermined pressure (P1), the displacement volume of the hydraulic pump increases as the delivery pressure of the hydraulic pump lowers from the predetermined pressure (p1). This makes it possible, even if the governor region is controlled to an isochronus characteristic, to increase the delivery rate of the hydraulic pump as the engine load becomes lighter.