摘要:
A precision servo control system for a pneumatic actuator has a piston (5) positionable over a stroke of the pneumatic actuator (2) using a supply of pressurized gas. A brake (52) and a sensor system (44) are connected to the actuator (2) and to the servo control system. The servo control system operates to initiate the forward thrust from the pressurized gas to move the piston (5) along the stroke. When a braking point along the stroke is determined, the servo control system initiates a reverse thrust from the pressurized gas while maintaining the forward thrust and simultaneously begins to selectively apply the brake (52) to stop the piston within a predetermined tolerance of a desired stopping position. The precision servo control system is easily programmable in a manner similar to that of a control system for electrical actuators. The precision servo control system can maintain the predetermined tolerance even under changing loads, long stroke lengths or vertically oriented stroke directions. The precision control servo system preferably utilizes simple directional valves, instead of complex and expensive servo valves, to regulate the pressurized gas. The precision servo control system achieves positional accuracy to a predetermined tolerance that is a fixed value, regardless of the stroke length.
摘要:
Es wird ein Verfahren zur Regelung der Bewegung einer Masse (13) angegeben, die von einem druckmittelbeaufschlagten hydraulischen Zylinder (11) über ein Getriebe (12) mit hubabhängiger Übersetzung, insbesondere eine Kniehebelanordnung, angetrieben ist. Die Eigenfrequenz derartiger Systemen ist sehr stark von der Position (xm) der Masse abhängig. Die Parameter der Regeleinrichtung müssen so eingestellt werden, daß auch bei der höchsten Eigenfrequenz keine Instabilität auftritt. Dies führt aber zu einem spürbaren Dynamikverlust in Bereichen mit niedriger Eigenfrequenz. Um die Parameter optimal für die Bereiche mit niedriger Eigenfrequenz einstellen zu können, ohne daß in Bereichen hoher Eigenfrequenz Instabilitäten auftreten, ist dem die Druckmittelzufuhr zu dem Zylinder steuernden Signal ein Beschleunigungssignal als Hilfsgröße (yn) überlagert, das in Abhängigkeit von der Position (xm) der Masse derart gewichtet wird, daß die Wirkung der Hilfsgröße auf den Regelvorgang in Bereichen hoher Eigenfrequenz des aus dem Zylinder, dem Getriebe und der Masse gebildeten Systems verringert wird. Das Verfahren kommt vorzugsweise zur Regelung der Bewegung von Kniehebelanordnungen, z. B. in Kunststoffmaschinen oder in Pressen, zum Einsatz.
摘要:
Es wird eine Vorrichtung zur Erfassung des Differenzdrucks in den Kammern (13, 14) eines Fluidzylinders (10) mittels einer Proportionalventilanordnung (15) vorgeschlagen. Dabei dient ein durch einen Differenzdruck-Sollwert (SW1 bzw. SW2) und einen Differenzdruck-Istwert (ÄP) beaufschlagbarer Druckregler (17) zur Regelung der Proportionalventilanordnung (15). Weiterhin sind Mittel zur Erfassung der Geschwindigkeit des Kolbens (11) im Fluidzylinder (10) vorgesehen, wobei der Geschwindigkeits-Istwert (v) als Einflussgröße zur Verringerung des Differenzdrucks dem Regelkreis zuführbar ist. Hierdurch wird in einfacher Weise erreicht, dass sofort ein von der gewünschten aufzubringenden Kraft abhängiger Differenzdruck-Sollwert (SW1) vorgegeben werden kann und dennoch die Bewegungsgeschwindigkeit des Kolbens (11) bzw. der Kolbenstange (12) in gewünschter Weise begrenzt werden kann, um einen zu heftigen Aufprall zu verhindern.
摘要:
A compact actuator (21) for use with a fluid and including a housing (31) having a predetermined geometry. An actuation member (41) is mounted in the housing for movement between first and second positions for performing work. The actuation member has first and second faces (46, 47). The housing has an assembly (61) for providing fluid to the first face for moving the actuation member to the first position and to the second face for moving the actuation member to the second position. The assembly includes at least one transducer (69, 83 and/or 84) having an active element (71, 86 and/or 87) which is changeable between a first shape when in the absence of an electromagnetic field and a second shape when in the presence of an electromagnetic field. A controller (146) and pumping apparatus (301) for use with the actuator are provided.
摘要:
With the position regulator according to the invention a first adjusting step and a second adjusting step are generated in order to prevent sustained oscillations about a constant desired value. The size of the first and second adjusting steps is such that, after the first adjusting step, the drive system is moved away from the desired value at least by the smallest increment and, after the second adjusting step, lies within a neutral zone in which a deviation is not corrected. Advantages of a pneumatic control valve with a position regulator of this type are lower air consumption and wear and greater regulating accuracy. The invention is used in pneumatic actuators.
摘要:
A valve control system for positioning a valve in response to a command signal. The valve control system comprises a sensor for detecting the position of the valve and for generating an outer feedback signal, a valve location command circuit for comparing the command signal to the outer feedback signal to generate a correction signal, an actuator for positioning the valve in response to pneumatic pressure, a spool slidably disposed within a block to direct pneumatic pressure to the actuator, a spool positioning device for moving the spool to a desired position, a spool sensor for detecting the current position of the spool and generating an inner feedback signal, and a spool location command for comparing the correction signal to the inner feedback signal to generate a spool positioning signal to direct the spool positioning device to move the spool to the desired position.
摘要:
Un entraînement hydraulique pour les mouvements de réglage, d'avancement et de retour d'une tête d'outil d'une machine-outil comprend un moteur hydraulique (11) et une soupape de régulation par poursuite (12). La valeur de référence de la position est fixée et la valeur réelle indiquée en retour au moyen d'une broche filetée (39) et d'un écrou de broche (37) se présentant sous la forme d'un arbre creux. L'un de ces deux éléments peut être entraîné par un moteur électrique (41) afin d'établir la valeur de référence de la position. L'autre élément peut être entraîné afin d'indiquer en retour la valeur de la position réelle. Un système indicateur de position rotative et angulaire (68, 74, 75 et 69, 77) produit un signal de sortie qui mesure directement le nombre total de révolutions exécutées par l'arbre à valeur de référence prédéfinie ainsi que sa position azimutale à l'intérieur de chaque révolution. Un système détecteur de position électronique (71, 78 et 71', 78'; 71'') produit un signal de sortie qui mesure l'erreur de poursuite DELTAS dont la position réelle de la tête d'outil ou de l'élément d'entraînement du moteur hydraulique (16) est en retard de phase par rapport à sa position de référence.
摘要:
An electrohydraulic set device including as an output set element a piston (26), which is operable by a hydraulic pressure against the action of return force. The hydraulic pressure is led to the working side of the piston via a valve passage (100, 108). The valve passage is opened and closed by an electromagnet operated control slide (82). The control slide (82) is arranged along a piston rod (28) connected to the piston (26) together with the coil (22) of the electromagnet the armature (76) being arranged therebetween, in a common chamber, of which the said working side of the piston forms part. A spring force (116) between the control slide (82) and the piston (26) tends to move the slide against the action of the magnet force in a direction closing the passage (100, 108).
摘要:
A fluid servo actuator comprises an input member (30) which can be rotated by drive means (24), (25) and which is provided with tubes (52), (44) capable of supplying and discharging hydraulic fluid and grooves (53(a), 53(b), 53(c), 53(d)) communicating with the tubes; an output member (4) which constitutes a shaft and which is provided with grooves (60(a), 60(b), 60(c), 60(d)) formed in the surface thereof facing the grooves in the input member and a tube (45) communicating with the grooves (60(a), 60(b), 60(c), 60(d)); an outer case (21), (22), (23) which hermetically seals the output and input members and houses the drive means; and working chambers (62a), (62b) which are defined between the outer case and the output member and which communicate with the tube in the output member, and which enable the output member to rotate by the supply and discharge of hydraulic fluid flowing through the tube. This fluid servo actuator makes it possible to reduce the size of the actuator body and simplify the hydraulic piping.
摘要:
A hydraulic control system for regulation of fluid flow rate, in which the fluid flow rate to and from a load actuator (28) is modulated by electric current in a single electromagnetic device (25) such that the flow rate is independent of load magnitude when the system is used without load velocity feedback and such that the flow rate is independent of both load magnitude and fluid viscosity when the system is used with load velocity feedback.