Abstract:
엔진(1)의 연료분사제어장치[전자 거버너(12) 및 제어기(13)]는 거버너영역을 등시특성으로 제어 가능하다. 작업기 제어기(18)는 토출압력신호(P)를 입력하여 유압펌프의 토출압력이 소정압력(P1)을 초과하면 유압펌프의 배기량이 미리 설정된 펌프흡수 토오크곡선(20)에 의하여 정해지는 값을 초과하지 않도록 레귤레이터(16)를 제어하고, 유압펌프(2)의 토출압력이 소정압력(P1) 이하에 있을 때, 유압펌프의 토출압력이 소정압력(P1)으로부터 낮아짐에 따라 유압펌프의 배기량이 증가하도록 레귤레이터(16)를 제어한다. 이에 의하여 거버너영역을 등시특성으로 제어되고 있더라도 엔진부하가 가벼워짐에 따라 유압펌프의 토출유량을 증가시킬 수 있다.
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.
Abstract:
Schaltungsanordnung zur Drehmomentsteuerung einer hydrostatischen Maschine an einem Hydrauliksystem mit eingeprägtem Betriebsdruck, mit einem mit dem Schwenkwinkel bzw. der Exzentrizität gekoppelten Geber zur Darstellung des Hubvolumenistwertes der Maschine, und mit einem willkürlich einstellbaren Drehmomentsollwert, der ein Regelsignal zur Ansteuerung eines Ventils zum betätigen eines Stellgliedes erzeugt, welches das das Drehmoment bestimmende Hubvolumen der Maschine unter Berücksichtigung der Betriebsparameter wie Druck, Drehzahl und Temperatur verändert, wobei folgendes vorgesehen ist der Schwenkwinkel (die Exzentrizität) wird analog oder digital gemessen und der Sollwert des Schwenkwinkels (oder der Exzentrizität) α= M P wird errechnet (analoge Lösung), oder aber die ausgegebene Spannung für die Schwenkwinkelvorgabe wird aus "vorher" festgelegten Meßwerten (digitale Lösung) bestimmt.
Abstract:
A rotary hydraulic machine such as a variable displacement in-line or axial piston pump including a housing (60), a shaft (66), a cylinder block (70), pistons (74) disposed therein and a valve block (62). A microprocessor-based controller (42) is externally mounted on the pump valve block (62) and includes internal memory having various remotely-selectable control programs prestored therein. Sensors (50, 52, 54) responsive to pump operating conditions are connected to the pump control electronics, and include a first sensor (50) responsive to yoke position, a pressure sensor (52) responsive to pump output pressure and a speed sensor (54) responsive to angular velocity of shaft rotation. All of the electronic components are mounted on the valve block (62).
Abstract:
An electronic closed loop piston pump servo control system including a swash plate within the pump housing which controls pump output as a function of its position about a rotational axis, means for altering the position of said swash plate, means for producing electric signals representative of the desired and actual swash plate angular positions and means for comparing these signals and producing a control or error signal to the means for altering the swash plate position as a function of these signal differences. The means for producing electric signals representative of the actual swash plate position includes a rotary potentiometer mounted in the pump housing and directly connected to the swash plate along a common axis of rotation. This potentiometer produces a d.c. signal indicating the angular position of the swash plate on this common axis. Afailsafe circuit is provided in the comparator means which prevents the error signal from affecting the swash plate angular position if the feedback signal falls below a predetermined reference level. The potentiometer rotates through h a relatively small arc such that when the sliding resistive contacts thereon are worn, the potentiometer contacts may be rotated to respond along a fresh arc.
Abstract:
A variable displacement pump control system comprising a variable displacement pump (10) having a movable element (11) for controlling pump displacement, a hydraulic motor (16) for moving the movable element (11), and a transducer (12) for producing an electric signal corresponding to the actual position of the movable element (11). A comparator (13) compares the electrical signal from the transducer (12) and an electrical signal corresponding to the desired displacement of the pump and produces an error signal. A control (20) operates in response to the error signal to meter fluid flow from the pump output (25) to the hydraulic motor (16). The control comprises a relief valve (18), a compensator valve (19) and a servo valve (20). The servo valve (20) is preferably a single-stage valve that includes damping orifices (47) to provide stability.
Abstract:
A sensor arrangement for determining an actual swashplate angle of a swashplate pivotally attached to a variable displacement hydraulic pump includes a control piston operable to control an angle of the swashplate relative to the variable displacement pump; a position marker arranged on the control piston; and a sensor arranged along the control piston to detect a movement of the position marker.