摘要:
An electro-hydraulic fluid metering and control device (10) with a position sensor (13) having a plane of geometric symmetry. The control device (10) includes a valve body (14) with a plurality of ports (22, 24, 26) and channels for fluid flow, a torque motor (11) mounted on the valve body (14) and responsive to an electrical driving signal, a valve, an armature (17) operating in the torque motor (11) and extending to operate the valve (14) and position sensor (13) and spring members for supporting the armature for pivotal movement to assure direct relationship between the valve (14) and moving member (39) of the position sensor.
摘要:
Die vorliegende Erfindung betrifft ein Proportionalventil (1) mit einem durch ein Steuersignal ansteuerbaren Vorsteuerventil (2) und einem mittels des Vorsteuerventils (2) betätigbaren Booster-Ventil (3), wobei das Proportionalventil (1) einen Druckluftanschluss (6) zum Anschluss einer Druckluftversorgung, einen Arbeitsanschluss (5) und einen Entlüftungsanschluss (4) aufweist. Das Booster-Ventil (3) weist drei einander nachgeschaltete und jeweils in einer axialen Richtung gegen eine Federkraft bewegliche Ventilelemente (8, 9, 10) auf. In einer Grundstellung des Proportionalventils (1) sind das erste, das zweite und das dritte Ventilelement (8, 9, 10) paarweise voneinander beabstandet und innerhalb des Booster-Ventils (3) sind ein zwischen dem ersten Ventilelement (8) und dem zweiten Ventilelement (9) wirksamer erster Dichtsitz (26) und ein zwischen dem dritten Ventilelement (10) und dem Gehäuse (16) wirksamer zweiter Dichtsitz (27) derart ausgebildet und angeordnet, dass bei Variation des das Vorsteuerventil (2) ansteuernden Steuersignals und einer hierdurch kaskadenartig bewirkten Verstellung der axialen Stellungen des ersten, zweiten und dritten Ventilelements (8, 9, 10) verschiedene Schaltzustände zum Entlüften und Belüften des Arbeitsanschlusses (5) und zum Halten eines am Arbeitsanschluss (5) anliegenden Drucks einstellbar sind. Ferner ist ein die axiale Stellung des ersten Ventilelements (8) erfassender Positionssensor (31) vorgesehen und eine Steuereinheit (36) des Proportionalventils (1) ist derart eingerichtet, dass zur Berechnung des zur Erzielung eines gewünschten Schaltzustands des Booster-Ventils (2) benötigten Steuersignals für das Vorsteuerventil (2) das Messsignal des Positionssensors (31) ausgewertet wird.
摘要:
A servovalve pilot stage assembly is provided having a first fluid conduit (152) having a first orifice (156), a second fluid conduit (154) having a second orifice (158), a flapper (44) having a deformable first region (176) disposed between the first orifice and the second orifice, an actuator (24) arranged to drive the flapper (44) from a first condition in which the first region of the flapper has a first width between the first and second orifice to a second condition in which the first region of the flapper has a second width between the first and second orifice, the second width being less than the first width.
摘要:
A servovalve assembly includes a motor having a flapper shaft (112). A flapper (114) couples to a first end of the flapper shaft such that the flapper shaft orients the flapper between a first nozzle (118) and a second nozzle (120) of the servovalve assembly. An adjustment assembly adjusts a position of the flapper relative to the nozzles of the servovalve. The adjustment assembly enables a servovalve manufacturer to set the flapper of the servovalve at a null position without disassembling the servovalve. Rather, the manufacturer is capable of simply installing the adjustment assembly and deforming an arm portion of the adjustment assembly for proper null position calibration.
摘要:
A control loop of a control valve is operated using outlet pressure from a pneumatic amplifier as the control parameter. The control loop may be operated continuously in pressure control mode, or may be switchedd from another mode, such as travel control mode, to pressure control mode in response to certain operating conditions such as operation in the cutoff range, operation with the throttling element engaging a travel stop, or as a backup in the event of primary control parameter sensor failure. Operating the control loop in pressure control mode further allows diagnostics to be performed on the control loop components, even when the system is operating in cutoff range or has engaged a travel stop. The diagnostics may be performed using pressure and displacement sensors normally provided with a positioner. A processor may be programmed to receive data from the sensors and generate fault signals according to a logic sub-routine. The logic sub-routine may include calculating mass flow of control fluid through pneumatic amplifier outlet ports and comparing other operating parameters to detect leaks and blockages in the control loop components. Once a fault is detected, the location of the root cause of the fault may be identified by characterizing operating parameters of the control loop at the time of the fault.
摘要:
A microvalve device for controlling fluid flow in a fluid circuit (10). The microvalve device comprises a body (12) having a cavity formed therein. The body further has first (20) and second (22) pilot ports placed in fluid communication with the cavity. The body also has first (28) and second (30) primary ports placed in fluid communication with the cavity. Each port is adapted for connection with a designated fluid source. A pilot valve (36) supported by the body is movably disposed in the cavity for opening and closing the first and second pilot ports. An actuator (38) is operably coupled to the pilot valve for moving the pilot valve. A microvalve (40) is positioned by the fluid controlled by the pilot valve. The microvalve is a slider valve having a first end (40a) and a second end (40b). The slider valve is movably disposed in the cavity for movement between a first position and a second position. The first end of the slider valve is in fluid communication with the first and second pilot ports when the first and second pilot ports are open. The second end of the slider valve is in constant fluid communication with the first primary port. When moving between the first and second positions, the slider valve at least partially blocks and unblocks the second primary port for the purpose of variably restricting fluid flow between the primary ports.
摘要:
A fluid control valve, comprising a valve block having a plurality of ports therein, a valve main body having ports formed therein corresponding to the ports in the valve block, and a plate disposed between the valve block and the valve main body, the plate further comprising a flow passage allowing the ports in the valve block to communicate with the ports in the valve main body, and having a filter disposed therein.
摘要:
A servovalve system comprising a pilot stage valve in communication with an hydraulic stage valve, the hydraulic stage valve comprising a valve member movably mounted in a valve chamber to selectively meter fluid flow in a flow path from an upstream inlet port to a downstream outlet port and at least two variable-sized orifices disposed in the flow path between the inlet and outlet ports, an upstream pressure sensor, a downstream pressure sensor, a fluid temperature sensor, a position sensor sensing a linear position of the valve member, a controller that receives input from the upstream pressure sensor, the downstream pressure sensor, the fluid temperature sensor and the position sensor; and the controller configured to provide a control signal to the pilot stage valve as a function of the input from the upstream pressure sensor, the downstream pressure sensor, the fluid temperature sensor and the position sensor.