EP0305306B1 - Hydraulic actuator with piston rod positioning means - Google Patents

Hydraulic actuator with piston rod positioning means Download PDF

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Publication number
EP0305306B1
EP0305306B1 EP88420290A EP88420290A EP0305306B1 EP 0305306 B1 EP0305306 B1 EP 0305306B1 EP 88420290 A EP88420290 A EP 88420290A EP 88420290 A EP88420290 A EP 88420290A EP 0305306 B1 EP0305306 B1 EP 0305306B1
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EP
European Patent Office
Prior art keywords
tie
drum
shaft
piston
jack
Prior art date
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Expired - Lifetime
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EP88420290A
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German (de)
French (fr)
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EP0305306A1 (en
Inventor
Pierre Clavel
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D'etudes Et De Montages Sdem SA Ste
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D'etudes Et De Montages Sdem SA Ste
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Priority to AT88420290T priority Critical patent/ATE57000T1/en
Publication of EP0305306A1 publication Critical patent/EP0305306A1/en
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    • 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
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/20—Other details, e.g. assembly with regulating devices
    • F15B15/28—Means for indicating the position, e.g. end of stroke
    • F15B15/2815—Position sensing, i.e. means for continuous measurement of position, e.g. LVDT
    • F15B15/283—Position sensing, i.e. means for continuous measurement of position, e.g. LVDT using a cable wrapped on a drum and attached to the piston

Definitions

  • the present invention relates to double-acting hydraulic cylinders and it relates more particularly (because it is in this case that its application seems to have the most interest, but not exclusively, the long stroke and high power cylinders.
  • US Pat. No. 4,121,504 had proposed having a shaft at the end of the cylinder cylinder which is oriented transversely to the longitudinal axis thereof and which carries, in addition a return spiral spring and an absolute encoder associated with a control automaton, a central drive drum controlled by a flexible link which is attached to the piston of the jack and which is wound in a helical groove dug in the periphery of said drum. It is understood that the encoder thus driven gives a perfectly precise indication of the position of the piston.
  • the main object of the present invention is to allow the production of a jack of the aforementioned type, the control of which remains perfectly precise whatever the stroke of the piston, even when this stroke is very long and reaches several meters.
  • the invention also relates to an actuator of the aforementioned type which is of robust and simple construction, while being able to be very easily maintained in operating condition throughout its use over time.
  • FIG. 1 shows in 1 the cylindrical body of a double-acting hydraulic cylinder, supplied by two end pipes 2 and 3.
  • the movable rod which carries the piston 5, and in 6 and 7 the two flanges terminals of which one (in the case considered that referenced 6), crossed by the rod 4, is used for fixing the assembly against a fixed support such as 8, while against the other 7 is normally applied the bottom transverse which closes the body 1 tightly.
  • this bottom is replaced by a cylindrical casing 9 oriented co-axially with the body 1, and which is provided with two end flanges, one of which 9a is fitted against the flange 7 while the other Qb receives the aforementioned fund, referenced 10.
  • the invention is of course applicable to cylinders in which the body 1 is supported, not by an end flange 6, but by pins such as those shown in 11 in FIG. 1, or by a perforated fastener of the kind shown in 11 1 in FIG. 2, which fastener, made integral with the flange 9b of the casing 9, is then shaped to play the role of closing bottom.
  • the casing 9 contains a shaft 12 oriented transversely to the axis of the body 1 and on the central part of which is keyed a drum 13.
  • the periphery of the latter is hollowed out by a groove 13a with helical profile for regular filling.
  • a flexible link formed by an inextensible cable 14 one end of which is fixed to one of the cheeks of said drum by means of a plate 15 (fig. 4), while the opposite end is made integral with the rear face of the piston 5 by means of an attachment 16 with double articulation.
  • Fig. 5 and 6 illustrate in detail the arrangement of the fastener 16.
  • the latter comprises a lug 17 shaped to secure the free end of the cable 14; this tab 17 pivots freely on a shaft 18 oriented longitudinally relative to the piston 5 and to the body 1 and itself supported by the ear 19a of a sleeve 19, which contains two bearings 20 which ensures the free rotation of said sleeve 19 on an axis 21 inserted axially in the rear face of the piston 5.
  • the double articulation system of the fastener 16 allows the cable 14, as and when re of its unwinding and its unwinding on the drum 13, to always remain oriented in a plane parallel to the longitudinal axis of the jack as well as to the plane passing through all the groove bottoms 13a of the drum 13, without any extension or contraction in length, regardless of the winding of said cable in the groove 13a. It will further be observed that this attachment system 16 completely frees the cable 14 from any rotation of the piston 5 inside the body 1 of the jack.
  • the transverse shaft 12 is mounted in two bearings 22 which it passes axially to cooperate on one side with the movable part of an absolute encoder 23, on the other with a tension spring 24.
  • Each bearing 22 is supported by a bush 25 which is made integral with the casing 9 and which contains a sealing part 26.
  • each part 26 is equipped with two annular seals 27 which are applied against the periphery of the shaft 12 and which are separated from each other by a radial bore 26g associated with a plug 26b for controlling the sealing.
  • An external seal 28 is opposed to any communication along the internal wall of each socket 25.
  • the input shaft of the absolute encoder 23 is connected to the end of the shaft 12 by means of a flexible anti-vibration connector 29 (fig. 3).
  • This encoder 23 is of course associated with an automaton (not shown), arranged to control the distributor which ensures the actuation of the piston 5 in either direction, this automaton itself being placed under the dependence of a computer for controlling the positioning of said piston according to the planned instruction.
  • the opposite protruding end of the shaft 12 enters an opening box 30 (fig. 7), closed by a removable cover 31.
  • the spring 24 is constituted by a blade wound in a spiral and held between two cheeks 32, the central part of which cooperates with bearings 33 bearing against a hub 34, which is keyed onto the considered end of the shaft 12.
  • an annular flange 36 whose outer edge is cut out with radial notches capable of being engaged on teeth 30a provided against the internal wall of the housing 30.
  • the cooperation of these notches and of these teeth 30a ensures the angular immobilization of the cheeks 32 inside the housing 30.
  • the inner end of the leaf spring 24 is secured to the hub 34 integral with the shaft 12, while the outer end is fixed to a small lever 37 (fig. 8) freely pivotally engaged on a tubular spacer 38 carried by one of the bolts 39 which join the two cheeks 32 to each other.
  • the assembly formed by the spring 24, the cheeks 32 and the hub 34 constitutes a kind of cartridge capable of being very easily assembled and disassembled with a view to its replacement.
  • the constant action of the spiral spring 34 on the shaft 12 ensures the permanent tension of the cable 14 during reciprocating movements of the piston 5 of the jack, radically avoiding any drive defect of the encoder 23, which can thus ensure a perfect identification precise position of said piston.
  • the invention lends itself particularly well to equipping existing jacks since it suffices to adapt the casing 9 to the body thereof instead of the bottom which usually closes this body.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Actuator (AREA)
  • Vehicle Body Suspensions (AREA)
  • Forklifts And Lifting Vehicles (AREA)

Abstract

1. Hydraulic jack with servo-controlled rodpositioning, of the type comprising a shaft (12) which is oriented transversely to the longitudinal axis of the body (1) and which bears, besides a spiral return spring (24) and an absolute encoder (23) associated with a control automat, a central drive drum (13) controlled by a supple tie (14) which is attached to the piston (5) and which winds in a helicoidal groove (13a) made in the wall of said drum, characterized in that the free end of the tie (14) is rendered fast with the rear face of the piston (5) by means of a fastener (16) comprising a tab (17) which is shaped to ensure fixation of the free end of the tie and which pivots freely on a shaft (18) oriented longitudinally with respect to said piston and supported by an ear (19_a) of a sleeve (19) which itself pivots freely on a pin (21) axially plugged in the rear face mentioned above, this double-articulation system enabling the tie, as it winds and unwinds on the drum, always to remain oriented in a plane parallel to the axis of the body of the jack as well as to the plane passing through all the groove bottoms (13_a) of the drum, without any extension or contraction of the length, whatever the winding of this tie in said groove.

Description

La présente invention a trait aux vérins hydrauliques à double effet et elle concerne plus particulièrement (car c'est dans ce cas que son application semble devoir comporter le plus d'intérêt, mais non exclusivement, les vérins à course longue et à grande puissance.The present invention relates to double-acting hydraulic cylinders and it relates more particularly (because it is in this case that its application seems to have the most interest, but not exclusively, the long stroke and high power cylinders.

On sait que dans un certain nombre de cas pratiques il est nécessaire de commander un vérin hydraulique de façon à ce que la succession des déplacements de sa tige mobile respecte une consigne d'extension et de contraction déterminée, laquelle consigne est susceptible d'être programmée manuellement sur le clavier d'un automate d'asservissement ou d'être dictée par un ordinateur. A l'heure actuelle les asservissements de positionnement sont obtenus à l'aide de servo-valves de construction complexe et de fiabilité réduite; au surplus et par suite de la difficulté d'obtention d'un signal continu et exact de la position de l'organe mobile du vérin, la précision de l'asservissement réalisé est très grossière et ne peut convenir lorsqu'on a affaire à des vérins à course très longue.We know that in a certain number of practical cases it is necessary to control a hydraulic cylinder so that the succession of displacements of its movable rod respects a set extension and contraction set point, which set point is likely to be programmed. manually on the keyboard of a servo controller or to be dictated by a computer. At present, positioning controls are obtained using servo valves of complex construction and reduced reliability; moreover and as a result of the difficulty of obtaining a continuous and exact signal of the position of the movable member of the jack, the precision of the control produced is very coarse and cannot be suitable when dealing with very long stroke cylinders.

Pour remédier à cet inconvénient, le Brevet US-A 4 121 504 (NOWAK) avait proposé de faire comporter à l'extrémité du cylindre du vérin un arbre qui est orienté transversalement à l'axe longitudinal de celui-ci et qui porte, outre un ressort spirale de rappel et un codeur absolu associé à un automate de commande, un tambour central d'entraînement commandé par un lien souple qui est attaché au piston du vérin et qui s'enroule dans une gorge hélicoïdale creusée dans la périphérie dudit tambour. On comprend que le codeur ainsi entraîné donne une indication parfaitement précise de la position du piston.To remedy this drawback, US Pat. No. 4,121,504 (NOWAK) had proposed having a shaft at the end of the cylinder cylinder which is oriented transversely to the longitudinal axis thereof and which carries, in addition a return spiral spring and an absolute encoder associated with a control automaton, a central drive drum controlled by a flexible link which is attached to the piston of the jack and which is wound in a helical groove dug in the periphery of said drum. It is understood that the encoder thus driven gives a perfectly precise indication of the position of the piston.

Il y a cependant lieu de considérer que ce document antérieur apporte une solution qui peut uniquement convenir pour des vérins comportant une course suffisamment réduite pour que la longueur de lien comprise entre la périphérie du tambour central d'entraînement et le piston reste absolument constante, du fait que toute modification de cette longueur introduirait une erreur sensible dans le fonctionnement du codeur.It should however be considered that this prior document provides a solution which can only be suitable for cylinders having a sufficiently short stroke so that the link length between the periphery of the central drive drum and the piston remains absolutely constant, from fact that any modification of this length would introduce a significant error in the operation of the encoder.

La présente invention a principalement pour but de permettre la réalisation d'un vérin du genre susvisé, dont l'asservissement reste parfaitement précis quelle que soit la course du piston, même lorsque cette course est très longue et atteint plusieurs mètres.The main object of the present invention is to allow the production of a jack of the aforementioned type, the control of which remains perfectly precise whatever the stroke of the piston, even when this stroke is very long and reaches several meters.

L'invention a également pour objet un vérin du genre susvisé qui soit de construction robuste et simple, tout en étant apte à être très aisément maintenu en état de fonctionnement tout au long de son utilisation dans le temps.The invention also relates to an actuator of the aforementioned type which is of robust and simple construction, while being able to be very easily maintained in operating condition throughout its use over time.

Le vérin hydraulique à positionnement de tige mobile asservi qui fait l'objet de l'invention est défini à la revendication 1.The hydraulic actuator with positioning of a movable rod controlled which is the subject of the invention is defined in claim 1.

Le dessin annexé, donné à titre d'exemple, permettra de mieux comprendre l'invention, les caractéristiques qu'elle présente et les avantages qu'elle est susceptible de procurer :

  • Fig. 1 est une vue en plan d'un vérin asservi réalisé conformément à l'invention.
  • Fig. 2 illustre une variante de mise en oeuvre de l'invention.
  • Fig. 3 est une coupe transversale à plus grande échelle suivant le plan indiqué en III-III en fig. 1.
  • Fig. 4 est une coupe de détail suivant IV-IV (fig. 3).
  • Fig. 5 montre à plus grande échelle encore l'agencement de l'attache à double articulation, montée sur le piston pour la fixation de l'extrémité libre du lien souple.
  • Fig. 6 est une coupe suivant VI-VI (fig. 5).
  • Fig. 7 représente en coupe le boîtier pour le ressort spirale et l'un des deux paliers de l'arbre.
  • Fig. 8 est une coupe suivant VIII-VIII (fig. 7).
The appended drawing, given by way of example, will allow a better understanding of the invention, the characteristics which it presents and the advantages which it is capable of providing:
  • Fig. 1 is a plan view of a slave cylinder produced in accordance with the invention.
  • Fig. 2 illustrates a variant implementation of the invention.
  • Fig. 3 is a cross section on a larger scale along the plane indicated in III-III in FIG. 1.
  • Fig. 4 is a detail section along IV-IV (fig. 3).
  • Fig. 5 shows on an even larger scale the arrangement of the double-articulated fastener, mounted on the piston for fixing the free end of the flexible link.
  • Fig. 6 is a section along VI-VI (fig. 5).
  • Fig. 7 shows in section the housing for the spiral spring and one of the two bearings of the shaft.
  • Fig. 8 is a section along VIII-VIII (fig. 7).

En fig. 1 on a représenté en 1 le corps cylindrique d'un vérin hydraulique à double effet, alimenté par deux canalisations d'extrémités 2 et 3. On aperçoit en 4 la tige mobile qui porte le piston 5, et en 6 et 7 les deux brides terminales dont l'une (dans le cas considéré celle référencée 6), traversée par la tige 4, est utilisée pour la fixation de l'ensemble contre un support fixe tel que 8, tandis que contre l'autre 7 est normalement appliqué le fond transversal qui ferme le corps 1 de manière étanche.In fig. 1 shows in 1 the cylindrical body of a double-acting hydraulic cylinder, supplied by two end pipes 2 and 3. We see in 4 the movable rod which carries the piston 5, and in 6 and 7 the two flanges terminals of which one (in the case considered that referenced 6), crossed by the rod 4, is used for fixing the assembly against a fixed support such as 8, while against the other 7 is normally applied the bottom transverse which closes the body 1 tightly.

En fait, dans le vérin suivant l'invention ce fond est remplacé par un carter cylindrique 9 orienté co- axialement au corps 1, et qui est pourvu de deux brides d'extrémités dont l'une 9a est rapportée contre la bride 7 tandis que l'autre Qb reçoit le fond susmentionné, référencé 10.In fact, in the jack according to the invention, this bottom is replaced by a cylindrical casing 9 oriented co-axially with the body 1, and which is provided with two end flanges, one of which 9a is fitted against the flange 7 while the other Qb receives the aforementioned fund, referenced 10.

Il convient ici d'observer que l'invention est bien entendu applicable aux vérins dans lesquels le corps 1 est supporté, non pas par une bride d'extrémité 6, mais par des tourillons tels que ceux représentés en 11 en fig. 1, ou par une attache perforée du genre de celle représentée en 11 1 en fig. 2, laquelle attache, rendue solidaire de la bride 9b du carter 9, est alors conformée pour jouer le rôle de fond de fermeture.It should be noted here that the invention is of course applicable to cylinders in which the body 1 is supported, not by an end flange 6, but by pins such as those shown in 11 in FIG. 1, or by a perforated fastener of the kind shown in 11 1 in FIG. 2, which fastener, made integral with the flange 9b of the casing 9, is then shaped to play the role of closing bottom.

Comme montré en fig. 3, le carter 9 renferme un arbre 12 orienté transversalement à l'axe du corps 1 et sur la partie centrale duquel est claveté un tambour 13. La périphérie de ce dernier est creusée d'une gorge 13a à profil hélicoidal pour l'envidage régulier d'un lien souple formé par un câble inextensible 14 dont une extrémité est fixée à l'une des joues dudit tambour à l'aide d'une plaquette 15 (fig. 4), tandis que l'extrémité opposée est rendue solidaire de la face arrière du piston 5 par l'intermédiaire d'une attache 16 à double articulation.As shown in fig. 3, the casing 9 contains a shaft 12 oriented transversely to the axis of the body 1 and on the central part of which is keyed a drum 13. The periphery of the latter is hollowed out by a groove 13a with helical profile for regular filling. of a flexible link formed by an inextensible cable 14, one end of which is fixed to one of the cheeks of said drum by means of a plate 15 (fig. 4), while the opposite end is made integral with the rear face of the piston 5 by means of an attachment 16 with double articulation.

Fig. 5 et 6 illustrent de manière détaillée l'agencement de l'attache 16. Celle-ci comprend une patte 17 conformée pour assurer la fixation de l'extrémité libre du câble 14 ; cette patte 17 pivote librement sur un arbre 18 orienté longitudinalement par rapport au piston 5 et au corps 1 et lui-même supporté par l'oreille 19a d'un manchon 19, lequel renferme deux roulements 20 qui assure la libre rotation dudit manchon 19 sur un axe 21 fiché axialement dans la face arrière du piston 5.Fig. 5 and 6 illustrate in detail the arrangement of the fastener 16. The latter comprises a lug 17 shaped to secure the free end of the cable 14; this tab 17 pivots freely on a shaft 18 oriented longitudinally relative to the piston 5 and to the body 1 and itself supported by the ear 19a of a sleeve 19, which contains two bearings 20 which ensures the free rotation of said sleeve 19 on an axis 21 inserted axially in the rear face of the piston 5.

On comprend que le système à double articulation de l'attache 16 permet au câble 14, au fur et à mesure de son envidage et de son dévidage sur le tambour 13, de rester toujours orienté dans un plan parallèle à l'axe longitudinal du vérin ainsi qu'au plan passant par tous les fonds de gorge 13a du tambour 13, sans aucune extension ou contraction de longueur, quel que soit l'enroulement dudit câble dans la gorge 13a. On observera en outre que ce système d'attache 16 affranchit totalement le câble 14 d'une éventuelle rotation du piston 5 à l'intérieur du corps 1 du vérin.It is understood that the double articulation system of the fastener 16 allows the cable 14, as and when re of its unwinding and its unwinding on the drum 13, to always remain oriented in a plane parallel to the longitudinal axis of the jack as well as to the plane passing through all the groove bottoms 13a of the drum 13, without any extension or contraction in length, regardless of the winding of said cable in the groove 13a. It will further be observed that this attachment system 16 completely frees the cable 14 from any rotation of the piston 5 inside the body 1 of the jack.

Comme montré en fig. 3, l'arbre transversal 12 est monté dans deux roulements 22 qu'il traverse axialement pour coopérer d'un côté avec la partie mobile d'un codeur absolu 23, de l'autre avec un ressort de tension 24. Chaque roulement 22 est supporté par une douille 25 qui est rendue solidaire du carter 9 et qui renferme une pièce d'étanchéité 26. A la manière illustrée en fig. 7, chaque pièce 26 est équipée de deux joints annulaires 27 qui sont appliqués contre la périphérie de l'arbre 12 et qui sont séparés l'un de l'autre par un perçage radial 26g associé à un bouchon 26b pour le contrôle de l'étanchéité. Un joint extérieur 28 s'oppose à toute communication le long de la paroi interne de chaque douille 25.As shown in fig. 3, the transverse shaft 12 is mounted in two bearings 22 which it passes axially to cooperate on one side with the movable part of an absolute encoder 23, on the other with a tension spring 24. Each bearing 22 is supported by a bush 25 which is made integral with the casing 9 and which contains a sealing part 26. In the manner illustrated in FIG. 7, each part 26 is equipped with two annular seals 27 which are applied against the periphery of the shaft 12 and which are separated from each other by a radial bore 26g associated with a plug 26b for controlling the sealing. An external seal 28 is opposed to any communication along the internal wall of each socket 25.

L'arbre d'entrée du codeur absolu 23 est relié à l'extrémité de l'arbre 12 au moyen d'un raccord flexible anti-vibration 29 (fig. 3). A ce codeur 23 est bien entendu associé un automate (non représenté), agencé pour commander le distributeur qui assure l'actionnement du piston 5 dans l'un et l'autre sens, cet automate étant lui-même placé sous la dépendance d'un ordinateur pour le contrôle du positionnement dudit piston suivant la consigne envisagée.The input shaft of the absolute encoder 23 is connected to the end of the shaft 12 by means of a flexible anti-vibration connector 29 (fig. 3). This encoder 23 is of course associated with an automaton (not shown), arranged to control the distributor which ensures the actuation of the piston 5 in either direction, this automaton itself being placed under the dependence of a computer for controlling the positioning of said piston according to the planned instruction.

L'extrémité dépassante opposée de l'arbre 12 pénètre dans un boîtier ouvrant 30 (fig. 7), fermé par un couvercle amovible 31. Le ressort 24 est constitué par une lame enroulée en spirale et maintenue entre deux joues 32 dont la partie centrale coopère avec des roulements 33 prenant appui contre un moyeu 34, lequel est claveté sur l'extrémité considérée de l'arbre 12.The opposite protruding end of the shaft 12 enters an opening box 30 (fig. 7), closed by a removable cover 31. The spring 24 is constituted by a blade wound in a spiral and held between two cheeks 32, the central part of which cooperates with bearings 33 bearing against a hub 34, which is keyed onto the considered end of the shaft 12.

Contre la joue 32 qui est tournée en direction du couvercle 31 est rapporté, par exemple à l'aide de vis telles que 35, un flasque annulaire 36 dont le bord extérieur est découpé d'entailles radiales aptes à être engagées sur des dents 30a prévues contre la paroi interne du boîtier 30. La coopération de ces entailles et de ces dents 30a assure l'immobilisation angulaire des joues 32 à l'intérieur du boîtier 30.Against the cheek 32 which is turned in the direction of the cover 31 is attached, for example using screws such as 35, an annular flange 36 whose outer edge is cut out with radial notches capable of being engaged on teeth 30a provided against the internal wall of the housing 30. The cooperation of these notches and of these teeth 30a ensures the angular immobilization of the cheeks 32 inside the housing 30.

L'extrémité intérieure du ressort à lame 24 est arrimée au moyeu 34 solidaire de l'arbre 12, tandis que l'extrémité extérieure est fixée à un petit levier 37 (fig. 8) librement engagé à pivotement sur une entretoise tubulaire 38 portée par l'un des boulons 39 qui assemblent l'une à l'autre les deux joues 32.The inner end of the leaf spring 24 is secured to the hub 34 integral with the shaft 12, while the outer end is fixed to a small lever 37 (fig. 8) freely pivotally engaged on a tubular spacer 38 carried by one of the bolts 39 which join the two cheeks 32 to each other.

On comprend que l'ensemble formé par le ressort 24, les joues 32 et le moyeu 34 constitue une sorte de cartouche susceptible d'être très aisément montée et démontée en vue de son remplacement. L'action constante du ressort spirale 34 sur l'arbre 12 assure la tension permanente du câble 14 au cours des déplacements alternatifs du piston 5 du vérin, en évitant radicalement tout défaut d'entraînement du codeur 23, lequel peut ainsi assurer un repérage parfaitement précis de la position dudit piston.It is understood that the assembly formed by the spring 24, the cheeks 32 and the hub 34 constitutes a kind of cartridge capable of being very easily assembled and disassembled with a view to its replacement. The constant action of the spiral spring 34 on the shaft 12 ensures the permanent tension of the cable 14 during reciprocating movements of the piston 5 of the jack, radically avoiding any drive defect of the encoder 23, which can thus ensure a perfect identification precise position of said piston.

On notera que l'invention se prête particulièrement bien à l'équipement des vérins existants puisqu'il suffit d'adapter au corps de ceux-ci le carter 9 aux lieu et place du fond qui ferme usuellement ce corps.It will be noted that the invention lends itself particularly well to equipping existing jacks since it suffices to adapt the casing 9 to the body thereof instead of the bottom which usually closes this body.

Claims (6)

1. Hydraulic jack with servo-controlled rodposi- tioning, of the type comprising a shaft (12) which is oriented transversely to the longitudinal axis of the body (1) and which bears, besides a spiral return spring (24) and an absolute encoder (23) associated with a control automat, a central drive drum (13) controlled by a supple tie (14) which is attached to the piston (5) and which winds in a helicoidal groove (13a) made in the wall of said drum, characterized in that the free end of the tie (14) is rendered fast with the rear face of the piston (5) by means of a fastener (16) comprising a tab (17) which is shaped to ensure fixation of the free end of the tie and which pivots freely on a shaft (18) oriented longitudinally with respect to said piston and supported by an ear (19a) of a sleeve (19) which itself pivots freely on a pin (21) axially plugged in the rear face mentioned above, this double-articulation system enabling the tie, as it winds and unwinds on the drum, always to remain oriented in a plane parallel to the axis of the body of the jack as well as to the plane passing through all the groove bottoms (13a) of the drum, without any extension or contraction of the length, whatever the winding of this tie in said groove.
2. Jack according to Claim 1, characterized in that the spiral spring (24) is maintained laterally between two cheeks (32) mounted idly on a central hub (34) keyed on the transverse shaft (12), one of said cheeks being angularly immobilized inside an openable casing (30-31
3. Jack according to Claim 2, characterized in that the inner end of the spiral spring (24) is fastened to the hub (34), whilst the outer end is fast with a pivoting lever (37) borne by one of the bolts (38) which assemble the two cheeks (32).
4. Jack according to any one of Claims 1 to 3, characterized in that the shaft (12) is borne by a housing (9) of cylindrical section which is provided with two end flanges (9a and 9b), of which one is adapted to be fixed against the corresponding flange (7) of the body (1), whilst the other receives a tight bottom (10) for closure.
5. Jack according to Claim 4, characterized in that there is associated with each of the two roller bearings (22) which support the transverse shaft (12) in the housing (9), a seal-holder element (26) which ensures tightness of said housing at the level of said shaft.
6. Jack according to any one of Claims 1 to 5, characterized in that a flexible anti-vibration connection (29) is interposed between the transverse shaft (12) and the encoder (23).
EP88420290A 1987-08-27 1988-08-25 Hydraulic actuator with piston rod positioning means Expired - Lifetime EP0305306B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT88420290T ATE57000T1 (en) 1987-08-27 1988-08-25 HYDRAULIC CYLINDER WITH PISTON TRAVEL INDICATOR DEVICE.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8712106 1987-08-27
FR8712106A FR2619870B1 (en) 1987-08-27 1987-08-27 HYDRAULIC CYLINDER WITH MOVABLE ROD POSITIONING

Publications (2)

Publication Number Publication Date
EP0305306A1 EP0305306A1 (en) 1989-03-01
EP0305306B1 true EP0305306B1 (en) 1990-09-26

Family

ID=9354527

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88420290A Expired - Lifetime EP0305306B1 (en) 1987-08-27 1988-08-25 Hydraulic actuator with piston rod positioning means

Country Status (4)

Country Link
EP (1) EP0305306B1 (en)
AT (1) ATE57000T1 (en)
DE (1) DE3860698D1 (en)
FR (1) FR2619870B1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107218267A (en) * 2017-06-01 2017-09-29 武汉船用机械有限责任公司 A kind of device for being used to detect hydraulic cylinder displacement

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2741400B1 (en) * 1995-11-22 1998-01-09 Valeo HYDRAULIC CYLINDER PROVIDED WITH MEANS FOR DETECTING THE AXIAL POSITION OF ITS PISTON
FR2794196B1 (en) 1999-05-31 2002-04-26 Pierre Clavel DEVICE FOR MEASURING AND CONTINUOUSLY DISPLAYING THE POSITION OR POSITION CONTROL OF A CYLINDER ROD
GB0101180D0 (en) * 2001-01-17 2001-02-28 Parkhouse Country Estates Ltd Platforms for use in transporters
CN100359190C (en) * 2003-08-07 2008-01-02 北京欧特科新技术有限公司 Built-in hydraulic oil-cylinder displacement sensor
CH704909A2 (en) * 2011-05-09 2012-11-15 Peter A Mueller Knitting cylinders with sensor.

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4121504A (en) * 1977-01-21 1978-10-24 Inovec, Inc. Cylinder positioning systems
US4286386A (en) * 1977-09-06 1981-09-01 Long Irvin E Electro-mechanical displacement measuring device
DE3106156A1 (en) * 1981-02-19 1982-09-09 Pohle + Rehling Gmbh, 4353 Oer-Erkenschwick Method of monitoring the face position and device for carrying out the method
DE3205773A1 (en) * 1982-02-18 1983-08-25 Vdo Adolf Schindling Ag, 6000 Frankfurt Pneumatic actuator
DE3229945C2 (en) * 1982-08-12 1986-06-05 Mannesmann Rexroth GmbH, 8770 Lohr Device for displaying the piston stroke in a hydraulic cylinder
DE8507512U1 (en) * 1985-03-14 1985-05-23 Knorr-Bremse GmbH, 8000 München Position indicator for a piston

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107218267A (en) * 2017-06-01 2017-09-29 武汉船用机械有限责任公司 A kind of device for being used to detect hydraulic cylinder displacement

Also Published As

Publication number Publication date
ATE57000T1 (en) 1990-10-15
FR2619870A1 (en) 1989-03-03
DE3860698D1 (en) 1990-10-31
EP0305306A1 (en) 1989-03-01
FR2619870B1 (en) 1992-11-13

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