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EP0051014B1 - Device for continuously controlling the stroke of a piston of an actuator - Google Patents

Device for continuously controlling the stroke of a piston of an actuator Download PDF

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Publication number
EP0051014B1
EP0051014B1 EP81401613A EP81401613A EP0051014B1 EP 0051014 B1 EP0051014 B1 EP 0051014B1 EP 81401613 A EP81401613 A EP 81401613A EP 81401613 A EP81401613 A EP 81401613A EP 0051014 B1 EP0051014 B1 EP 0051014B1
Authority
EP
European Patent Office
Prior art keywords
piston
chamber
rod
cam
cylinder
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP81401613A
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German (de)
French (fr)
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EP0051014A1 (en
Inventor
Roger Jarniac
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Original Assignee
Commissariat a lEnergie Atomique CEA
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Publication of EP0051014A1 publication Critical patent/EP0051014A1/en
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Publication of EP0051014B1 publication Critical patent/EP0051014B1/en
Expired legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F3/00—Devices, e.g. jacks, adapted for uninterrupted lifting of loads
    • B66F3/24—Devices, e.g. jacks, adapted for uninterrupted lifting of loads fluid-pressure operated
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B9/00—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member
    • F15B9/16—Systems essentially having two or more interacting servomotors, e.g. multi-stage
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B9/00—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member
    • F15B9/02—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type
    • F15B9/08—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type controlled by valves affecting the fluid feed or the fluid outlet of the servomotor
    • F15B9/10—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type controlled by valves affecting the fluid feed or the fluid outlet of the servomotor in which the controlling element and the servomotor each controls a separate member, these members influencing different fluid passages or the same passage

Definitions

  • the present invention relates to a device allowing a continuous adjustment of the stroke of the piston of a jack, applicable in particular in the case of a differential piston.
  • Figure 4 of this document illustrates a variant in which the piston has the shape of a cam integral with its rod and making an angle other than 90 ° with the latter. The cam thus separates the cylinder containing the piston into two compartments while a pressurized fluid inlet opens into this cylinder.
  • the shape of the cam is such that during the rotation of the shaft, the fluid inlet opens either in one compartment or in the other. A continuous back and forth movement of the piston is thus obtained, but the amplitude of this movement is determined once and for all by the shape of the cam.
  • compressed air is sent to each of the ends of the cylinder containing the piston.
  • Several discharge orifices closed by valves themselves controlled by solenoids, are distributed along this cylinder. The opening of one of these valves causes the evacuation of the compressed gas and therefore a vacuum on one side of the cylinder. The piston then moves back to the level of the selected orifice.
  • a step-by-step adjustment of the piston stroke is thus obtained by the choice of one of the discharge orifices, but, in all possible levels, the amplitude of the stroke remains the same since it is determined by the shape of the cam constituting the piston. It is not possible to adjust this amplitude continuously and, moreover, such a device is quite complex, and therefore costly to produce, because the discharge orifices can be quite numerous and each valve is controlled by a solenoid.
  • the object of the present invention is precisely to eliminate these drawbacks by proposing a simple device which makes it possible to continuously vary the stroke of the piston.
  • this piston forming part of a cylinder comprising a control member movable relative to the piston, at least part of this control member being in the form of a rod movable in rotation and in translation
  • this rod comprises an extension having the form of a differential piston movable in rotation and in translation inside a cylinder and defining inside thereof a chamber with a large section and a chamber with a small section, the latter being permanently in communication with a source of fluid under high pressure by means of an orifice provided in the wall of said cylinder, the piston differential having an internal cavity inside which is disposed a second rod immobilized in translation and being able to be angularly oriented, said second rod being provided with a cam having two edges o positioned, this cam being able to uncover and seal cyclically, during the rotation of the differential piston, on the one hand at least a first orifice formed in the wall of the piston and putting the large
  • the second rod has a cavity which allows, thanks to one of said orifices, to put the large-section chamber in communication with a fluid discharge.
  • said differential piston comprises an outer wall on which are hollowed out at least two grooves, the ends of one of these grooves opening into one of said orifices and into the chamber with a large section respectively , the ends of the other groove opening respectively into the other orifice and into the small section chamber.
  • the jack shown in FIGS. 2 to 4 comprises a tubular cylindrical body 1 in the axial bore of which a piston 2 is slidably mounted which thus defines two opposite chambers respectively referenced 3 and 4.
  • This piston 2 is itself provided in the form tubular, the axial housing 5 thus determined extending partially inside the motor member 6 operated by said piston.
  • the drive member 6 having a diameter greater than that of the shaft 7, the piston 2 can be described as 'differential'.
  • chamber 3 will hereinafter be called “with small section” while chamber 4 will be “with large section”.
  • the small-section chamber 3 is permanently connected to a source of fluid under high pressure by means of two opposite radial slots 11. Moreover, the shaft 7 extends beyond the discharge slots 10 to exit axially of the cylinder 1 of the jack and receive the drive of a motor 12 associated with an appropriate transmission 13.
  • this shaft 7 which is engaged in the housing 5 is solilitary, by machining or by fixing a cam 14 whose figure 5 shows the profile clearly; in the example considered, it is a double sinusoidal profile which extends symmetrically in two parts around the cylinder formed by said shaft.
  • This 1z cam. opposes the communication of the large section chamber 4 with the discharge channel 8, and its two opposite edges are intended to form shutters for two pairs of radial orifices 15 and 16, drilled in the thickness of the piston 2; each of the orifices 15 is connected by a peripheral groove 17 to the chamber with large section 4, while similar grooves 18 ensure the communication of the orifices 16 with the chamber with small section 3, it being understood that these two pairs of grooves 17 and 18 are profiled so as not to intersect.
  • the motor 12 is started and drives the shaft 7 and the cam 14 in the dextrorotatory direction, the edge or lower part of said cam will discover the two orifices 16; the hydraulic fluid can thus pass from the chamber 3 to the chamber 4 through the aforementioned orifices and the grooves 18.
  • the chamber 4 having a larger useful section, the piston 2 moves upwards.
  • this axial displacement of the piston tends to bring the orifices 16 below the lower edge of the cam 14, but as the latter is rotated, said orifices remain uncovered as long as this cam has not - made a 90 ° rotation.
  • the orifices 16 are closed by the lower edge of the cam 14, while the upper edge of the latter uncovers the two orifices 15.
  • the chamber 4 is thus placed in communication with the bass pressure through the grooves 17, the orifices 15, the channel 8 and the ports 10, while the high pressure is exerted on the upper face of the piston which, consequently, moves downwards.
  • This downward movement of the piston 2 and of the member 6 will continue for a time corresponding to a 90 ° rotation of the shaft 7, so that things will end up in the position of FIG. 2, and that a new operating cycle may then occur.
  • Figure 1 shows how such an actuator can be associated with an adjustment device according to 1, invention.
  • the piston 22 is similar to the piston 2; it is slidably mounted in a cylinder 21 provided with lights 31 and 30 respectively connected to the high and to the low pressures of the general installation.
  • the piston 22 is a differential piston which delimits in the cylinder 21 a chamber 23 with a small section and a chamber 24 with a large section.
  • a cam 34 carried by a second rod 27 which is not driven in a rotational movement: this shaft 27 protrudes beyond the free transverse face of the cylinder 21 to be equipped a member allowing the adjustment of its orientation, which member has been shown diagrammatically in the form of a lever 19.
  • There are also on the piston 22 orifices 35, 36 and grooves 37, 38 which play the same role as the holes 15, 16 and the grooves 17, 18 of the piston 2.
  • the extension 40 of the rod 7 must be rotated by the motor 12 without this drive being able to oppose its axial displacement under the effect of the piston 22.
  • the transmission interposed between the motor 12 and the part 40 is therefore formed by two pinions or toothed wheels 41 with straight teeth.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Structural Engineering (AREA)
  • Actuator (AREA)

Description

La présente invention à pour objet un dispositif permettant un réglage continu de la course du piston d'un vérin, applicable notamment dans le cas d'un piston'différentiel.The present invention relates to a device allowing a continuous adjustment of the stroke of the piston of a jack, applicable in particular in the case of a differential piston.

Il existe à l'heure actuelle de nombreux dispositifs permettant de faire varier la longueur de la course d'un piston comme, par exemple, celui décrit dans le document US-A-2 898 890. La figure 4 de ce document illustre une variante dans laquelle le piston a la forme d'une came solidaire de sa tige et faisant avec cette derniere un angle different de 90°. La came sépare ainsi en deux compartiments le cylindre contenant le piston tandis qu'une arrivée de fluide sous pression débouche dans ce cylindre.There are currently many devices for varying the length of the stroke of a piston such as, for example, that described in document US-A-2 898 890. Figure 4 of this document illustrates a variant in which the piston has the shape of a cam integral with its rod and making an angle other than 90 ° with the latter. The cam thus separates the cylinder containing the piston into two compartments while a pressurized fluid inlet opens into this cylinder.

La forme de la came est telle qu'au cours de la rotation de l'arbre, l'arrivée de fluide débouche soit dans un compartiment, soit dans l'autre. On obtient ainsi un mouvement aller et retour continu du piston, mais l'amplitude de ce mouvement est déterminée une fois pour toutes par la forme de la came.The shape of the cam is such that during the rotation of the shaft, the fluid inlet opens either in one compartment or in the other. A continuous back and forth movement of the piston is thus obtained, but the amplitude of this movement is determined once and for all by the shape of the cam.

Dans le mode de réalisation illustre à la figure 10 de ce même document, on envoie de l'air comprime à chacune des extrémités du cylindre contenant le piston. Plusieurs orifices d'évacuation, fermés par des soupapes elles-mémes commandées par des solénoides, sont répartis le long de ce cylindre. L'ouverture d'une de ces soupapes provoque l'évacuation du gaz comprimé et donc une dépression d'un côté du cylindre. Le piston recule alors jusqu,au niveau de l'orifice sélectionné. On obtient ainsi un réglage pas à pas de la course du piston par le choix de l'un des orifices d'évacuation, mais, dans tous les niveaux possibles, l'amplitude de la course reste la même puisqu'elle est déterminée par la forme de la came constituant le piston. 11 n'est pas possible de régler cette amplitude de maniere continue et, de plus, un tel dispositif est assez complexe, et donc coùteux à réaliser, car les orifices d'évacuation peuvent être assez nombreux et chaque soupape est commandée par un solénîde.In the embodiment illustrated in FIG. 10 of this same document, compressed air is sent to each of the ends of the cylinder containing the piston. Several discharge orifices, closed by valves themselves controlled by solenoids, are distributed along this cylinder. The opening of one of these valves causes the evacuation of the compressed gas and therefore a vacuum on one side of the cylinder. The piston then moves back to the level of the selected orifice. A step-by-step adjustment of the piston stroke is thus obtained by the choice of one of the discharge orifices, but, in all possible levels, the amplitude of the stroke remains the same since it is determined by the shape of the cam constituting the piston. It is not possible to adjust this amplitude continuously and, moreover, such a device is quite complex, and therefore costly to produce, because the discharge orifices can be quite numerous and each valve is controlled by a solenoid.

La présente invention a justement pour objet d'éliminer ces inconvenients en proposant un dispositif simple et permettant de faire varier d'une manière continue la course du piston.The object of the present invention is precisely to eliminate these drawbacks by proposing a simple device which makes it possible to continuously vary the stroke of the piston.

Selon la principale caractéristique du dispositif de réglage en continu de l'amplitude de la course d'un piston objet de l'invention, ce piston faisant partie d'un vérin comportant un organe de commande mobile par rapport au piston, au moins une partie de cet organe de commande se présentant sous la forme d'une tige mobile en rotation et en translation, cette tige comporte un prolongement ayant la forme d'un piston différentiel mobile en rotation et en translation à l'intérieur d'un cylindre et définissant à l'intérieur de celui-ci une chambre à grande section et une chambre à petite section, cette dernière étant en permanence en communication avec une source de fluide sous haute pression au moyen d'un orifice prévu dans la paroi dudit cylindre, le piston différentiel présentant une cavité interne à l'intérieur de laquelle est disposée une deuxième tige immobilisée en translation et pouvant être orientée angulairement, ladite deuxième tige étant munie d'une came comportant deux bords opposés, cette came pouvant découvrir et obturer cycliquement, au cours de la rotation du piston différentiel, d'une part au moins un premier orifice ménagé dans la paroi du piston et mettant en communication la chambre à grande section avec la chambre à petite section et, d'autre part, au moins un deuxième orifice ménagé dans la paroi du piston et mettant la chambre à grande section en communication avec un systeme d'evacuation de fluide.According to the main characteristic of the device for continuously adjusting the amplitude of the stroke of a piston which is the subject of the invention, this piston forming part of a cylinder comprising a control member movable relative to the piston, at least part of this control member being in the form of a rod movable in rotation and in translation, this rod comprises an extension having the form of a differential piston movable in rotation and in translation inside a cylinder and defining inside thereof a chamber with a large section and a chamber with a small section, the latter being permanently in communication with a source of fluid under high pressure by means of an orifice provided in the wall of said cylinder, the piston differential having an internal cavity inside which is disposed a second rod immobilized in translation and being able to be angularly oriented, said second rod being provided with a cam having two edges o positioned, this cam being able to uncover and seal cyclically, during the rotation of the differential piston, on the one hand at least a first orifice formed in the wall of the piston and putting the large section chamber into communication with the small section chamber and , on the other hand, at least a second orifice formed in the wall of the piston and putting the chamber with a large section in communication with a fluid evacuation system.

Selon une autre caractéristique de ce dispositif, la deuxieme tige comporte une cavité qui permet, gràce à l'un desdits orifices, de mettre en communication la chambre à grande section avec une évacuation de fluide.According to another characteristic of this device, the second rod has a cavity which allows, thanks to one of said orifices, to put the large-section chamber in communication with a fluid discharge.

Enfin, suivant une dernière caractéristique de ce dispositif, ledit piston différentiel comprend une paroi extérieure sur laquelle sont creusées au moins deux rainures, les extrémités de l'une de ces rainures débouchant dans l'un desdits orifices et dans la chambre à grande section respectivement, les extrémités de l'autre rainure debouchant respectivement dans l'autre orifice et dans la chambre à petite section.Finally, according to a last characteristic of this device, said differential piston comprises an outer wall on which are hollowed out at least two grooves, the ends of one of these grooves opening into one of said orifices and into the chamber with a large section respectively , the ends of the other groove opening respectively into the other orifice and into the small section chamber.

L'invention apparaitra mieux à la lecture de la description qui va suivre, donnée à titre purement illustratif et nullement limitatif, d'un exemple de réalisation dans lequel le dispositif objet de l'invention est appliqué à un vérin d'actionnement à commande programmée comportant lui-méme un piston différentiel commandé par une tige équipée d'une came.The invention will appear better on reading the description which follows, given for purely illustrative and in no way limitative, of an exemplary embodiment in which the device which is the subject of the invention is applied to an actuating cylinder with programmed control itself comprising a differential piston controlled by a rod equipped with a cam.

Le principe de fonctionnement d'un tel vérin étant le même que celui du dispositif de réglage objet de l'invention, on décrira d'abord en détail le fonctionnement de ce vérin, puis on montrera comment la course du piston peut être modifiée gràce au dispositif selon l'invention.The operating principle of such a cylinder being the same as that of the adjustment device object of the invention, we will first describe in detail the operation of this cylinder, then we will show how the stroke of the piston can be changed thanks to device according to the invention.

Cette description sera faite en référence aux dessins annexés sur lesquels :

  • - la figure 1 est une vue schématique en coupe d'un vérin hydraulique d'actionnement à commande programmée équipé d'un dispositif de réglage conforme à l'invention,
  • - la figure 2 est une vue schématique en coupe d'un vérin hydraulique d'actionnement à commande programmée semblable à celui de la figure 1, mais sans le dispositif de réglage d'amplitude,
  • - les figures 3 et 4 reproduisent partiellement la figure 2 à deux positions différentes du piston mobile, et
  • - la figure 5 est une vue en perspective de la came portée par la tige de commande du vérin illustré aux figures 2 à 4.
This description will be made with reference to the appended drawings in which:
  • FIG. 1 is a schematic sectional view of a hydraulic actuator with programmed control equipped with an adjustment device according to the invention,
  • FIG. 2 is a schematic sectional view of a hydraulic actuator with programmed control similar to that of FIG. 1, but without the amplitude adjustment device,
  • FIGS. 3 and 4 partially reproduce FIG. 2 at two different positions of the movable piston, and
  • FIG. 5 is a perspective view of the cam carried by the control rod of the jack illustrated in FIGS. 2 to 4.

Le vérin représenté sur les figures 2 à 4 comprend un corps cylindrique tubulaire 1 dans l'alésage axial duquel est monté à coulissement un piston 2 qui definit ainsi deux chambres opposées respectivement référencées 3 et 4. Ce piston 2 est lui-même prévu sous forme tubulaire, le logement axial 5 ainsi determiné se prolongeant partiellement à l'intérieur de l'organe moteur 6 manoeuvré par ledit piston. A l'intérieur du logement borgne 5 précité est engagé un arbre ou tige 7 à plus petit diametre, creusé d'un canal axial 8 dont une extrémité débouche dans la partie borgne du logement 5 tandis que l'extrémité opposée est reliée par des perçages radiaux à deux lumières d'évacuation 10 qui communiquent elles-mêmes avec la basse pression de l'installation hydraulique.The jack shown in FIGS. 2 to 4 comprises a tubular cylindrical body 1 in the axial bore of which a piston 2 is slidably mounted which thus defines two opposite chambers respectively referenced 3 and 4. This piston 2 is itself provided in the form tubular, the axial housing 5 thus determined extending partially inside the motor member 6 operated by said piston. Inside the abovementioned blind housing 5 is engaged a shaft or rod 7 of smaller diameter, hollowed out with an axial channel 8, one end of which opens into the blind part of the housing 5 while the opposite end is connected by bores radial with two discharge lights 10 which themselves communicate with the low pressure of the hydraulic installation.

L'organe moteur 6 présentant un diamètre supérieur à celui de l'arbre 7, le piston 2 peut être qualifié de 'différentiel'. Bien que les deux chambres soient établies au même diamètre la chambre 3 sera ci-après dite 'à petite section' tandis que la chambre 4 sera 'à grande section'. On notera que la chambre à petite section 3 est en permanence reliée à une source de fluide sous haute pression grâce à deux lumières radiales opposées 11. par ailleurs, l'arbre 7 se prolonge au-delà des lumières d'évacuation 10 pour sortir axialement du cylindre 1 du vérin et recevoir l'entraînement d'un moteur 12 associé à une transmission appropriée 13.The drive member 6 having a diameter greater than that of the shaft 7, the piston 2 can be described as 'differential'. Although the two chambers are established at the same diameter, chamber 3 will hereinafter be called “with small section” while chamber 4 will be “with large section”. It will be noted that the small-section chamber 3 is permanently connected to a source of fluid under high pressure by means of two opposite radial slots 11. moreover, the shaft 7 extends beyond the discharge slots 10 to exit axially of the cylinder 1 of the jack and receive the drive of a motor 12 associated with an appropriate transmission 13.

La partie de cet arbre 7 qui se trouve engagée dans le logement 5 est solilaire, par usinage ou par fixation d'une came 14 dont la figure 5 fait bien voir le profil; dans l'exemple considéré, il s'agit d'un profil sinusoïdal double qui s'étend symétriquement en deux parties autour du cylindre formé par ledit arbre. Cette came 1z. s'oppose à la communication de la chambre à grande section 4 avec le canal d'évacuation 8, et ses deux bords opposés sont destinés à former des obturateurs pour deux paires d'orifices radiaux 15 et 16, perces dans l'épaisseur du piston 2; chacun des orifices 15 est relié par une rainure peripherique 17 à la chambre à grande section 4, tandis que des rainures semblables 18 assurent la communication des orifices 16 avec la chambre à petite section 3, étant entendu que ces Zeux paires de rainures 17 et 18 sont profilées pour ne pas s'intersecter.The part of this shaft 7 which is engaged in the housing 5 is solilitary, by machining or by fixing a cam 14 whose figure 5 shows the profile clearly; in the example considered, it is a double sinusoidal profile which extends symmetrically in two parts around the cylinder formed by said shaft. This 1z cam. opposes the communication of the large section chamber 4 with the discharge channel 8, and its two opposite edges are intended to form shutters for two pairs of radial orifices 15 and 16, drilled in the thickness of the piston 2; each of the orifices 15 is connected by a peripheral groove 17 to the chamber with large section 4, while similar grooves 18 ensure the communication of the orifices 16 with the chamber with small section 3, it being understood that these two pairs of grooves 17 and 18 are profiled so as not to intersect.

Le fonctionnement de ce vérin découle des explications qui précèdent et se comprend aisément.The operation of this cylinder follows from the foregoing explanations and is easily understood.

En figure 2, on a supposé que le moteur 12 associé à l'arbre 7 était à l'arrêt et que la came 14 se trouvait à une orientation telle que les quatre orifices 15 et 16 étaient recouverts par les bords de ladite came et étaient de ce fait obturés. Le fluide sous haute pression qui, dans cet exemple, est un liquide hydraulique, pénètre bien dans la chambre à petite section 3 et tend à repousser le piston 2 vers le bas, mais comme la chambre opposée 4 est séparée par la came 14 des lumières d'évacuation 10, ledit piston reste immobile.In FIG. 2, it has been assumed that the motor 12 associated with the shaft 7 was stopped and that the cam 14 was in an orientation such that the four orifices 15 and 16 were covered by the edges of said cam and were thereby closed. The fluid under high pressure which, in this example, is a hydraulic liquid, penetrates well into the chamber with small section 3 and tends to push the piston 2 downwards, but since the opposite chamber 4 is separated by the cam 14 of the lights evacuation 10, said piston remains stationary.

Si au contraire, comme montré en figure 3, le moteur 12 est mis en marche et entraîne l'arbre 7 et la came 14 dans le sens dextrogyre, le bord ou làvre inférieure de ladite came va découvrir les deux orifices 16 ; le liquide hydraulique peut ainsi passer de la chambre 3 à la chambre 4 à travers les orifices précités et les rainures 18. La chambre 4 présentant une section utile plus grande, le piston 2 se déplace vers le haut. Bien entendu, ce déplacement axial du piston tend à ramener les orifices 16 en deçà du bord inferieur de la came 14, mais comme celle-ci est entraînée en rotation, lesdits orifices restent découverts aussi longtemps que cette came n'aura pas - effectué une rotation de 90°.If on the contrary, as shown in FIG. 3, the motor 12 is started and drives the shaft 7 and the cam 14 in the dextrorotatory direction, the edge or lower part of said cam will discover the two orifices 16; the hydraulic fluid can thus pass from the chamber 3 to the chamber 4 through the aforementioned orifices and the grooves 18. The chamber 4 having a larger useful section, the piston 2 moves upwards. Of course, this axial displacement of the piston tends to bring the orifices 16 below the lower edge of the cam 14, but as the latter is rotated, said orifices remain uncovered as long as this cam has not - made a 90 ° rotation.

A ce moment et comme illustré en figure 4, les orifices 16 se trouvent obtures par le bord inférieur de la came 14, tandis que le bord superieur de cette derniere découvre les deux orifices 15. La chambre 4 est ainsi mise en communication avec la basse pression à travers les rainures 17, les orifices 15, le canal 8 et les lumières 10, alors que la haute pression s,exerce sur la face supérieure du piston qui, en conséquence, se déplace vers le bas. Ce déplacement du piston 2 et de l'organe 6 vers le bas va se poursuivre pendant un temps correspondant à une rotation de 90° de l'arbre 7, si bien que les choses vont se retrouver à la position de la figure 2, et qu'un nouveau cycle de fonctionnement pourra alors survenir.At this time and as illustrated in FIG. 4, the orifices 16 are closed by the lower edge of the cam 14, while the upper edge of the latter uncovers the two orifices 15. The chamber 4 is thus placed in communication with the bass pressure through the grooves 17, the orifices 15, the channel 8 and the ports 10, while the high pressure is exerted on the upper face of the piston which, consequently, moves downwards. This downward movement of the piston 2 and of the member 6 will continue for a time corresponding to a 90 ° rotation of the shaft 7, so that things will end up in the position of FIG. 2, and that a new operating cycle may then occur.

Il y a bien entendu lieu de prévoir des organes d'étanchéité propres à éviter toute communication parasite entre les chambres du cylindre et les orifices du piston 2 lors du coulissement de celui-ci. De la même manière, il est indispensable d'associer à ce piston des moyens d'immobilisation angulaire au cours de son déplacement alternatif. Moyennant ces precautions, on obtient un fonctionnement parfait du vérin dont l'organe 6 est asservi à suivre une loi de mouvement bien déterminée, laquelle est fonction du profil de la came tournante 14.It is of course necessary to provide sealing members capable of avoiding any parasitic communication between the chambers of the cylinder and the orifices of the piston 2 during the sliding thereof. Likewise, it is essential to associate angular immobilization means with this piston during its reciprocating movement. With these precautions, perfect operation of the jack is obtained, the member 6 of which is slaved to follow a well-defined law of movement, which is a function of the profile of the rotating cam 14.

La figure 1, montre comment un tel vérin peut être associé à un dispositif de réglage selon 1,invention.Figure 1 shows how such an actuator can be associated with an adjustment device according to 1, invention.

Sur cette figure, on retrouve le cylindre 1 avec ses lumières radiales 10 et 11 pour sa liaison avec l'installation hydraulique, le piston différentiel 2 percé d'orifices radiaux 15-16 et creusé de rainures de communication 17-18, et la came tournante 14 qui est portée par l'arbre 7 monté à rotation dans l'alésage axial borgne 5 dudit piston. Toutefois, l'arbre 7 qui porte la came 14 est ici solidaire d'une piece 40 qui se prolonge axialement vers le bas pour former le piston 22 d'un second verin hydraulique à commande programmee.In this figure, we find the cylinder 1 with its radial lights 10 and 11 for its connection with the hydraulic installation, the differential piston 2 pierced with radial holes 15-16 and hollowed out with communication grooves 17-18, and the cam rotary 14 which is carried by the shaft 7 rotatably mounted in the blind axial bore 5 of said piston. However, the shaft 7 which carries the cam 14 is here integral with a part 40 which extends axially downward to form the piston 22 of a second hydraulic cylinder with programmed control.

Le piston 22 est semblable au piston 2; il est monte à coulissement dans un cylindre 21 pourvu de lumières 31 et 30 respectivement raccordees à la haute et à la basse pressions de l'installation générale. Le piston 22 est un piston différentiel qui délimite dans le cylindre 21 une chambre 23 à petite section et une chambre 24 à grande section. Dans le logement borgne 25 du piston 22 est engagée une came 34 portee par une deuxieme tige 27 qui n'est pas animée d'un mouvement de rotation: cet arbre 27 dépasse au-delà de la face transversale libre du cylindre 21 pour être équipé d'un organe permettant le réglage de son orientation, lequel organe a été schématisé sous la forme d'un levier 19. On retrouve également sur le piston 22 des orifices 35, 36 et des rainures 37, 38 qui jouent le même rôle que les orifices 15, 16 et les rainures 17, 18 du piston 2.The piston 22 is similar to the piston 2; it is slidably mounted in a cylinder 21 provided with lights 31 and 30 respectively connected to the high and to the low pressures of the general installation. The piston 22 is a differential piston which delimits in the cylinder 21 a chamber 23 with a small section and a chamber 24 with a large section. In the blind housing 25 of the piston 22 is engaged a cam 34 carried by a second rod 27 which is not driven in a rotational movement: this shaft 27 protrudes beyond the free transverse face of the cylinder 21 to be equipped a member allowing the adjustment of its orientation, which member has been shown diagrammatically in the form of a lever 19. There are also on the piston 22 orifices 35, 36 and grooves 37, 38 which play the same role as the holes 15, 16 and the grooves 17, 18 of the piston 2.

Bien entendu, le prolongement 40 de la tige 7 doit être entraîné en rotation par le moteur 12 sans que cet entraînement puisse s'opposer à son déplacement axial sous l'effet du piston 22. La transmission interposée entre le moteur 12 et la pièce 40 est donc formée par deux pignons ou roues dentées 41 à denture droite.Of course, the extension 40 of the rod 7 must be rotated by the motor 12 without this drive being able to oppose its axial displacement under the effect of the piston 22. The transmission interposed between the motor 12 and the part 40 is therefore formed by two pinions or toothed wheels 41 with straight teeth.

Le fonctionnement de l'ensemble représente en figure 1 se conçoit sans peine. Le vérin supérieur travaille idedtiquement et dans les memes conditions qu'en figures 2 à 4, de telle sorte que l'organe 6 se déplace alternativement vers le haut et vers le bas en fonction du programme imparti par la came tournante 14. Pour le verin inférieur, la rotation du piston 22 se substitue en quelque sorte à celle de la came et de ce fait ledit piston 22 coulisse axialement ; le levier 19 permet, par modification de la position angulaire de la came 34 dans le piston 22, de régler, non pas l'amplitude de la course de ce dernier, mais le moment précis où cette course intervient, On conçoit dans ces conditions que, suivant le dephasage des deux vérins de l'ensemble représente en figure 1, on peut obtenir que la course de l'un s'ajoute a la course de l'autre ou s'en retranche, si bien que l'utilisateur est finalement en mesure de regler de façon exacte l'amplitude du déplacement de l'organe 6 porté par le piston 2.The operation of the assembly shown in Figure 1 is easily understood. The upper actuator works identically and under the same conditions as in FIGS. 2 to 4, so that the member 6 moves alternately up and down depending on the program set by the rotating cam 14. For the actuator lower, the rotation of the piston 22 somehow replaces that of the cam and therefore said piston 22 slides axially; the lever 19 makes it possible, by modifying the angular position of the cam 34 in the piston 22, to adjust, not the amplitude of the stroke of the latter, but the precise moment when this stroke occurs. It is conceivable under these conditions that , depending on the phase shift of the two cylinders of the assembly represents in FIG. 1, it is possible to obtain that the travel of one adds to the travel of the other or subtracts from it, so that the user is finally able to adjust the amplitude of the displacement exactly of the member 6 carried by the piston 2.

Comme on l'a indiqué plus haut, l'agencement du dispositif suivant la figure 1 a été représenté de manière très schématique et l'on doit notamment prévoir des joints, garnitures ou autres moyens propres à assurer l,étanchéité du coulissement des pistons 2 et 22.As indicated above, the arrangement of the device according to FIG. 1 has been shown very schematically and in particular provision must be made for seals, linings or other means suitable for ensuring the sealing of the sliding of the pistons 2 and 22.

Il est bien entendu que l'invention ne se li- mite pas au seul exemple qui vient d'être décrit, mais qu'on peut envisager des variantes sans sortir pour autant du cadre de l'invention, notamment remplacer certains détails d'exécution par tous autres équivalents. Enfin, si on a décrit une application particulière dans laquelle le dispositif objet de l'invention est associé à un piston différentiel, celui-ci peut s'appliquer à n'importe quel type de vérin dont le piston est muni d'un organe de commande.It is understood that the invention is not limited to the single example which has just been described, but that it is possible to envisage variants without departing from the scope of the invention, in particular replacing certain details of execution. by all other equivalents. Finally, if a particular application has been described in which the device which is the subject of the invention is associated with a differential piston, this can be applied to any type of cylinder whose piston is provided with a ordered.

Claims (3)

1. Apparatus for continuously controlling the amplitude of the stroke of a piston (2) of an actuator, the latter comprising a control member which is moveable with respect to the piston (2), at least one part of said control member constituting a rod (7) which is moveable in rotation and in translation, characterized in that said rod (7) has a prolongation in the form of a differential piston (22) which is moveable in rotation and in translation within a cylinder (21) and defining, in the interior of the latter, a widesection chamber (24) and a narrow-section chamber (23), said latter being permanently in communication with a source of high pressure fluid by means of an orifice (31) in the wall of cylinder (21), the differential piston (22) having an internal cavity (25) within which is located a second rod (27) which is immobile in translation and angularly orientable, said second rod (27) having a cam (34) having two opposed edges, said cam (34) being adapted to uncover and close cyclically, during the course of rotation of the differential piston (22) on the one hand,of at least one orifice (35) formed in the wall of piston (22) and establishing communication between the wide-section chamber (24) and the narrow-section chamber (23) and, on the other hand, at least one orifice (36) formed in the wall of piston (22) and providing communication between the wide-section chamber (24) and 2 fluid exit port.
2. Apparatus according to claim 1, characterized in that the second rod (27) has a cavity (28) which, because of one (36) of said orifices, provides communication between the wide-section chamber (24) and a fluid exit port (30).
3. Apparatus according to either of claims 1 or 2, characterized in that said differential piston (22) comprises an external wall in which are formed at least two grooves (37,38), the ends of one (37) of said grooves opening respectively into one (35) of said orifices and into the wide-section chamber (24), the ends of the other groove (38) opening respectively into the other orifice (36) and into the narrowsection chamber (23).
EP81401613A 1980-10-23 1981-10-15 Device for continuously controlling the stroke of a piston of an actuator Expired EP0051014B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8023066A FR2492909A1 (en) 1980-10-23 1980-10-23 IMPROVEMENTS TO PROGRAMMED CONTROL HYDRAULIC ACTUATORS
FR8023066 1980-10-23

Publications (2)

Publication Number Publication Date
EP0051014A1 EP0051014A1 (en) 1982-05-05
EP0051014B1 true EP0051014B1 (en) 1986-02-05

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EP81401613A Expired EP0051014B1 (en) 1980-10-23 1981-10-15 Device for continuously controlling the stroke of a piston of an actuator

Country Status (8)

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US (1) US4426912A (en)
EP (1) EP0051014B1 (en)
JP (1) JPS5798498A (en)
KR (1) KR830007421A (en)
AU (1) AU543842B2 (en)
DE (1) DE3173730D1 (en)
FR (1) FR2492909A1 (en)
YU (1) YU252181A (en)

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Publication number Priority date Publication date Assignee Title
EP1067293A3 (en) * 1999-07-09 2003-11-19 Parker Hannifin Corporation Electro-hydraulic actuator and method for controlling actuator position
US6995585B2 (en) 2003-08-05 2006-02-07 International Business Machines Corporation System and method for implementing self-timed decoded data paths in integrated circuits
US20160333901A1 (en) * 2015-05-15 2016-11-17 Triumph Engine Control Systems, Llc Fail fixed actuator
CN112830412B (en) * 2020-12-31 2022-04-05 上海同力建设机器人有限公司 Semi-automatic quick hand change lifting device

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2898890A (en) * 1957-07-16 1959-08-11 Ibm Motion transmitting device

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR464891A (en) * 1912-11-27 1914-04-02 Octave Brotelle Antiseptic felt pad with plastics bands, serving as a hernia bandage
US2970570A (en) 1959-03-23 1961-02-07 L A B Corp Hydraulic vibrator
US3368457A (en) * 1964-08-19 1968-02-13 Chrysler Corp Hydraulic control arrangement
JPS5129440Y1 (en) 1970-12-26 1976-07-24

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2898890A (en) * 1957-07-16 1959-08-11 Ibm Motion transmitting device

Also Published As

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AU543842B2 (en) 1985-05-02
KR830007421A (en) 1983-10-21
EP0051014A1 (en) 1982-05-05
YU252181A (en) 1984-02-29
FR2492909B3 (en) 1983-09-16
JPS5798498A (en) 1982-06-18
FR2492909A1 (en) 1982-04-30
DE3173730D1 (en) 1986-03-20
US4426912A (en) 1984-01-24
AU7650881A (en) 1982-04-29

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