Abstract:
Die Erfindung betrifft ein Verfahren zum Anzeigen der Stellung einer hydraulisch betätigten Armatur mit einem Kolben (121) in einem Stellzylinder (1.2) zum Betätigen der Armatur (1.1), der über zwei Hydraulikleitungen (2, 3) mit einem Umschaltventil (7) verbunden ist, durch das die Hydraulikleitungen zwischen druckführendem Vorlauf und drucklosem Rücklauf umgeschaltet werden können, wobei die Strömung des durch eine der Hydraulikleitungen strömenden Hydraulikfluids in eine Anzahl von elektrischen Impulsen umgewandelt wird, von denen jeder einer vorgegebenen Volumeneinheit des Hydraulikfluids entspricht, das Umschaltventil (7) an Versorgungsleitungen (P, T) angeschlossen ist, an denen weitere Umschaltventile zum Betätigen weiterer Armaturen (In) angeschlossen sind, die Umschaltventile (7) über eine Abzweigleitung (T1) an die für alle Armaturen gemeinsame Rücklaufleitung (T) angeschlossen sind, und wobei an jedem Umschaltventil (7) in der Abzweigleitung (T1) zur Rücklaufleitung (T) ein Vorspanndruck aufrechterhalten wird, der höher ist als der Druck in der gemeinsamen Rücklaufleitung (T). Weiterhin führt ein Programm, das die Impulse des Durchflusssensors verarbeitet, einen Lernzyklus durch.
Abstract:
유압시스템의 최고 압력을 설정하는 메인 릴리프밸브의 초기 셋팅 압력을 일정하게 유지하기 위한 건설기계용 압력 자동 제어장치를 개시한다. 본 발명에 따른 건설기계용 압력 자동 제어장치에 있어서, 엔진과, 메인 유압펌프 및 파일럿 펌프와, 유압 액츄에이터와, 컨트롤밸브와, 조작레버와, 메인 릴리프밸브를 구비하는 건설기계에 적용되며, 메인 유압펌프와 메인 릴리프밸브 사이의 유로에 설치되며 릴리프시 유압시스템의 설정 압력을 실시간으로 검출하여 검출신호를 출력하는 제1압력센서와, 상기 메인 릴리프밸브와 유압탱크 사이의 유로에 설치되며 릴리프시 메인 릴리프밸브의 출구측 압력을 실시간으로 검출하여 검출신호를 출력하는 제2압력센서와, 메인 릴리프밸브의 셋팅 압력을 조정하기 위해 입력되는 제어신호에 비례 또는 반비례하도록 파일럿 압력을 생성하여 메인 릴리프밸브에 출력하는 전자비례제어밸브와, 제1,2압력센서들로부터 실시간으로 입력되는 검출신호에 따라 메인 릴리프밸브의 셋팅 압력을 가변 조정할 수 있는 제어신호를 전자비례제어밸브에 출력하는 제어부를 포함하는 것을 특징으로 하는 건설기계용 압력 자동 제어장치를 제공한다.
Abstract:
Offenbart wird eine hydraulische Steueranordnung mit einer Eingangsdruckwaage bestehend aus einem Proportionalwegeventil (1), dessen eine Steuerseite (Y) mit einem gedrosselten Verbraucherlastdruck sowie einer Vorspannfeder und dessen andere Steuerseite (X) mit einem gedrosselten Pumpendruck beaufschlagt ist und einem hydraulisch gesteuerten Schaltventil (ZV1) zum wählweisen gedrosselten Verbinden der beiden Steuerseiten des Proportionalwegeventils (1). Des Weiteren ist ein zusätzliches vorzugsweise elektromagnetisch betätigtes Schaltventil vorgesehen, das wahlweise eine Bypassleitung zum hydraulisch betätigten Schaltventil öffnet, um eine gedrosselte Bypass-Verbindung zwischen den beiden Steuerseiten des Proportionalwegeventils zwangszuschalten.
Abstract:
Die Erfindung betrifft eine Druckregelventilein- richtung, insbesondere eine Überströmventileinrichtung oder Druckbegrenzungsventileinrichtung, mit einem Druckanschluss und mit einem gegen die Feder-kraft einer Ventilfedereinrichtung und den dort herrschenden Druck in einen Ventilkolbenaufnahmeraum hinein bewegbaren Ventilkolben, der eine Strö- mungsverbindung zwischen dem Druckanschluss und einer Absteueröffnung, die mit einer Druckentspannungsleitung (4) in Verbindung steht, freigibt, wenn ein vorgegebener Druck überschritten wird, wo- bei der Ventilkolbenaufnahmeraum über eine Volumen- ausgleichsöffnung (48) und eine Volumenausgleichs- verbin-dungsleitung (18) mit der Druckentspannungs- leitung (4) in Verbindung steht. Um eine Druckregelventileinrichtung zu schaffen, durch die auf der Druckseite ein nahezu konstanter Druck eingestellt werden kann, ist zwischen der Volumenausgleichsöffnung und der Druckentspannungsleitung (4) eine Drosseleinrichtung (19;49) vorgesehen.
Abstract:
A power machine (10) includes one or more steerable wheels (14). The wheels (14) are steerable using a hydraulic actuator (202, 204) to drive steering movement of the wheels (14). The power machine (10) also includes steering angle sensors (302, 304) which sense the steering angle and provide a signal indicative of the angle at which the wheels (14) are disposed relative to a longitudinal axis of the power machine (10). A hydraulic control system controls pressure of hydraulic fluid provided to the steering actuators (202, 204) based upon the steer angle position and desired change in position over time sensed by the steer angle sensors (302, 304).
Abstract:
An electrohydraulic proportional control valve assembly (1) for controlling a bidirectional fluid actuated device (7) has a first actuating port (4) for bidirectional fluid flow between the assembly and a first port of the device (7), a second actuating port (5) for bidirectional fluid flow between the assembly and a secondport of the device (7), a pump port (15, 16) for input fluid flow from a pump (17), and a tank port (18, 19) for output fluid flow from a tank (20). The assembly (1) comprises a first spool valve (2) connected to the first actuating port (4), the pump port (15, 16) and the tank port (18, 19) for controlling the direction and rate of fluid flow to and from the first port of the device (7), and a second spool valve (3) connected to the second actuating port (5), the pump port (15, 16) and the tank port (18, 19) and operable independently of the first pool valve 2 for controlling the direction and rate of fluid flow to and from the second port of the device (7). A position sensing arrangement (23, 24) is provided for supplying electrical position signals indicative of the actual positions of the spools (12, 13) of the first and second spool valves (2, 3) and a pressure sensing arrangement (26, 27, 28 and 29) is provided for supplying electrical pressure signals indicative of the fluid pressures in the first and second actuating ports (4, 5), the pump port (15, 16) and the tank port (18, 19). A servo control (not shown) controls the positions of the first and second spools (2, 3) in dependence on the electrical position and pressure signals and in response to an electrical demand signal provided in response to operator actuation, in order to set the throughflow cross sections for fluid flow to effect the required control of the device (7).
Abstract:
The invention relates to a hydraulic control arrangement for the demand-feed regulated hydraulic fluid supply of preferably several hydraulic consumers which are provided with proportionally adjustable directional control valves (12). A required amount of hydraulic fluid can be delivered by two hydraulic pumps (30, 31) via a common supply line leading to the directional control valves. A first demand-feed regulator (45) is associated with the first hydraulic pump (30) and a second demand-feed regulator (46) is associated with the second hydraulic pump (31). A return valve (36) which opens into the feed line is mounted between the first hydraulic pump (30) and the feed line (26). According to the invention, a return valve (37) that opens into the feed line (26) is also arranged between the second hydraulic pump (31) and the feed line (26). Means (90, 91, 95, 96) for regulating the power use of the demand-feed regulator (45, 46) are provided, whereby said means can be modified in such a way that the hydraulic consumers can be exclusively supplied with hydraulic fluid by the first hydraulic pump (30) or the second hydraulic pump (31).
Abstract:
An oil passage slit (20) that is formed in the valve disc (50) of a flow dividing valve (5-1), a control chamber (70) and oil passage (31-1) are connected to a signal transmission oil passage (9), the oil passage slit (20) being formed with a lap portion (32) having a check valve function with a lap quantity X at the shut-off position of the valve disc (50), the oil passage (31-1) having a 2-position 3-way valve (11) installed therein. The valve (11) connects the control chamber (70) of the flow dividing valve (5-1) to the signal transmission oil passage (9) alone when there is no external signal (F), while when the external signal (F) is applied, it connects the control chamber (70) both to the signal transmission oil passage (9) and to a low pressure detection oil passage (35) connected to the outlet passage (5b) of a flow dividing valve (5-2) on the side of a hydraulic actuator (3-2). This ensures that during composite operation driving an inertial body, the pressure on the low load pressure side is detected as a signal pressure without shutting off a load pressure detection oil passage on the high load pressure side and that the portion for detecting the load pressure is simplified and the flow dividing function is not impaired.
Abstract:
An electrohydraulic conversion valve (3a) such as a cylinder controlling control valve (3) is connected to the output side of a controller (23) for performing a control computing based on an operation electric signal from an electric joystick (12a) or the like. A control valve return pressure (PT) and a load sensing pressure (PL) are detected by first and second pressure detectors (18), (19) and the start of a hydraulic cylinder (7) is detected by a rise of the pressure difference ( DELTA P) between these pressures. The controller (23) is provided with a function generator (14a) having a standard function (F) for setting the relation between an operation electric signal and an instruction value to the electrohydraulic conversion valve (3a) and the like and with a calibration computing unit (20) for modifying the standard function (F). The calibration computing unit (20) computes a deviation ( DELTA S) between an instruction value set by the standard function (F) at the start of the cylinder and an instruction value stored at the actual start of the cylinder and adds the deviation to the standard function (F).