EP0284482A1 - Differential hydraulic jack for operating electric breakers - Google Patents

Differential hydraulic jack for operating electric breakers Download PDF

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Publication number
EP0284482A1
EP0284482A1 EP88400574A EP88400574A EP0284482A1 EP 0284482 A1 EP0284482 A1 EP 0284482A1 EP 88400574 A EP88400574 A EP 88400574A EP 88400574 A EP88400574 A EP 88400574A EP 0284482 A1 EP0284482 A1 EP 0284482A1
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EP
European Patent Office
Prior art keywords
piston
cylinder
valve
cylinder according
chamber
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EP88400574A
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German (de)
French (fr)
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EP0284482B1 (en
Inventor
Claude Alain Gratzmuller
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Individual
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Individual
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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
    • F15B15/08—Characterised by the construction of the motor unit
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/02—Details
    • H01H33/28—Power arrangements internal to the switch for operating the driving mechanism
    • H01H33/30—Power arrangements internal to the switch for operating the driving mechanism using fluid actuator
    • H01H33/34—Power arrangements internal to the switch for operating the driving mechanism using fluid actuator hydraulic

Definitions

  • the present invention relates to a differential hydraulic cylinder for controlling electric circuit breakers, of the type in which the annular chamber of the cylinder, defined by the interior surface of the cylinder of the cylinder and by the exterior surface of the outgoing rod of the piston, is permanently connected. to a high pressure hydraulic source.
  • the outgoing rod of the jack is coupled to the movable contact of the circuit breaker and a supply / bleed orifice, formed in the bottom of the main chamber of the jack, can be selectively connected to said high pressure source ("Supply” position) to repel the piston, or to a low pressure tank (“Purge” position) to let the piston return to its initial position under the effect of the high pressure P prevailing in the annular chamber.
  • a supply / bleed orifice formed in the bottom of the main chamber of the jack
  • the first maneuver brings out the piston rod and brings the circuit breaker into the latched or closed position, while the second maneuver brings the rod back into the cylinder and brings the circuit breaker into the tripped or open position.
  • differential cylinders for this application, presents constructive difficulties, in particular because they must guarantee a permanent and absolute tightness, for very long periods, despite the very high hydraulic operating pressures P, of the order of 300 to 400 bar and high speeds of the order of 10 to 15 meters / second.
  • These jacks must therefore include at least, as shown in the aforementioned prior patent, a first seal at the passage of the outgoing rod through the bottom of the cylinder and a second seal on the piston.
  • the first of these fittings is relatively easy to produce in order to obtain an absolute seal. Indeed, this packing is fixed and it is easy to obtain a rectified and polished piston rod which does not wear the packing. On the other hand, the piston rod, which is full, does not vary in diameter under the effect of the pressure and the packing is practically not subjected to pressure variations since the annular chamber is always subjected to the pressure permanent P supplied by an oleopneumatic accumulator constituting the source of pressurized hydraulic fluid.
  • this seal mounted on the piston, is movable and is subjected to strong accelerations and to shocks from the the fact that the maneuvers are carried out in very short times, less than a few 1 / 100th seconds; it is subjected to strong pressure variations between the engaged and triggered positions; the cylinder expands under the influence of pressure (of the order of 300 to 400 bar); the inner surface of the cylinder must be perfectly rectified and polished to preserve the integrity of the lining; finally, at the end of the triggering stroke, the lining can be subjected to considerable overpressures (several thousand bar) which are detrimental to the holding of the lining if certain precautions are not taken, which lead to structural complications.
  • piston linings have only been able to be produced satisfactorily in relatively complicated and expensive forms (on which numerous patents have been filed).
  • spring packings are used which are formed from one or more rings of elastic material kept compressed by a spring.
  • An example of such a spring seal is shown in Figure 2 of the aforementioned prior patent.
  • piston linings can only cooperate with a perfectly polished cylinder surface.
  • the differential cylinders still have the drawback that a duct or passage of large cross section must be provided for rapid transfer, at high speed, between the master bedroom and the annular chamber of the jack. Indeed, the circuit-breaker engagement or tripping maneuvers (that is to say the outward stroke or the return stroke of the cylinder piston) must be carried out in a very short time, of the order of a few hundredths of a second, which means that braking by a slower circulation of oil must be avoided.
  • the object of the present invention is to remedy the drawbacks of differential hydraulic cylinders known up to now and to allow much simpler and economical construction while ensuring even better reliability thanks to the reduction in the number of components.
  • engagement stroke will be used to designate the displacement of the piston from the bottom of the main chamber to the bottom of the annular chamber and the term “trigger stroke” to designate the return displacement. piston in reverse.
  • the subject of the invention is a differential hydraulic cylinder of the type defined in the foregoing in which the piston does not have a seal cooperating with the interior surface of the cylinder of the cylinder, and in which the piston is mechanically associated with a valve ensuring the permanent tight closure of the supply / bleed orifice of the main chamber of the jack when the piston is in the tripping end position.
  • the external cylindrical surface of the piston is in substantially direct sliding contact, metal on metal, with the internal surface of the cylinder.
  • there is of course an oil leak between the piston and the cylinder but the inventor has discovered that this leak was negligible during the movements of the piston, in one direction or in the other, which only last a few hundredths of a second.
  • the valve is integral with the aforementioned opposite face of the piston and the valve seat is formed at the periphery of the supply / drain orifice of the main chamber.
  • this arrangement of the piston devoid of packing provides other important advantages, in particular the possibility of producing the cylinder in the form of a foundry piece requiring only simple machining, which would be incompatible. with a piston seal. Furthermore, it is possible to bring directly from the foundry the transfer channel of large section between the main chamber and the annular chamber of the jack, which considerably reduces the number of constituent parts of the jack.
  • This control comprises a differential cylinder 2 comprising a cylinder 4, a piston 6, an outgoing piston rod 8 which is coupled to the movable contact 10 of a circuit breaker to establish or cut the circuit between the fixed contacts 12-12 ⁇ of the circuit breaker.
  • the position shown in Figure 1 is the tripped position of the circuit breaker (open contacts), in which the piston 6 is close to its low position in the cylinder.
  • the annular chamber 14 of the jack situated above the piston 6 and surrounding the piston rod 8 is permanently connected, by a pipe 15, to a high-pressure oleopneumatic accumulator 18 (for example 300 to 400 bar), the pressure in this chamber 14 tending to permanently return the circuit breaker to the tripped position.
  • a high-pressure oleopneumatic accumulator 18 for example 300 to 400 bar
  • a passage or orifice 28 which can be selectively connected, by a supply / purge pipe 22, on which is interposed a three-way valve 24, or, via a line 22 ⁇ and a transfer line 16, to the accumulator 18 or, via a line 25, to a pressure-based purge tank 26 (position shown in Figure 1).
  • Triggering is obtained by placing the valve 24 in the purge position (position in Figure 1).
  • Known differential cylinders such as that shown in FIG. 1, include a seal 30 on the passage of the outgoing rod 8 through the bottom 32 of the cylinder and, also, a seal 34 on the piston 6 to ensure the seal between the piston and the interior surface of the cylinder 4.
  • This seal has been shown in the known form of a spring seal of the kind shown in FIG. 2 of the aforementioned prior patent and it must ensure the permanent seal of the chamber 14, under the pressure of approximately 300 to 400 bar, in the triggered position shown.
  • Figure 2 attached is a sectional view of a differential cylinder according to the invention, all the elements already described bearing the same reference number.
  • a seal 30 is provided for the passage of the piston rod 8 through the target bottom 32 of the cylinder 4, but the piston 6 of the jack is devoid of any seal ensuring the seal between the piston 6 , made of metal, and cylinder 4, made of metal.
  • the outer cylindrical surface 36 of the piston 6 slides substantially directly, metal on metal, on the inner surface 38 of the cylinder 4, but without ensuring the seal between these two surfaces and without the surface 38 having a particularly precise machining. .
  • the piston 6 carries, under its underside 40, a projecting part forming a frusto-conical valve 42 adapted to close, at the end of the triggering stroke (position shown in FIG. 2), the supply / bleed orifice 28, which is at low pressure in the end-of-trip position shown in solid lines in FIG. 2.
  • the valve 42 can be fitted in a sealed manner on a frustoconical valve seat 44 formed, on the edge of the orifice 28, in the screwed bottom 46 of the cylinder.
  • the valve seat 44 can be constituted by an insert, of material of hardness suitable for that of the valve, in the bottom of the cylinder 46.
  • the valve 42 is applied on its seat 44 and closes the passage 48 in leaktight manner, which at the same time determines an end of stroke stop for the piston. .
  • the pressure P permanently prevailing in the annular chamber 14 cannot therefore escape through the purge passage and there is therefore no permanent circulation of oil which should be compensated by a pump (not shown) recharging the accumulator 18.
  • the pressure P prevailing in the annular chamber 14 can at most gain, by the leak existing between the piston 6 and the cylinder, the underside of the piston 6, that is to say the volume, at this reduced moment, of the main chamber 20.
  • the piston 6 is therefore subjected to the pressure P both on its upper annular surface "S1-s" and on its lower annular surface "S1-S2", S2 being the section of the valve 42.
  • the section S2 of the valve must be significantly greater than the section s of the rod, for example of the order of 50%. Good results have been obtained with values between 25% and 100%.
  • FIG. 2 shows a frustoconical valve 42 linked to the piston, but any other type of valve can be chosen, for example a valve of the ball valve type in which the shutter member is a sphere or a portion of a sphere 48 ( FIG. 3) or else a flat valve (FIG. 4) constituted by the upper face 50 of the bottom 46 of the cylinder against which a circular lip 52 machined is machined in the lower surface 54 of the piston 6.
  • a flat valve FIG. 4
  • the reverse arrangement, in which the sealing lip is carried by the upper face 50 of the bottom of the cylinder could also be used.
  • One can provide, to cooperate with the lip 52, an annular lining 56 of suitable material.
  • the valve may be integral with, or form an integral part of, the piston 6, as shown in FIGS. 2 and 4, or else it may have a certain degree of freedom, as it is shown in FIG. 3 where the hemispherical valve 48 is engaged. in a housing 58, formed in the piston 6, where it is retained by an elastic ring 60. Finally, one can provide, as in FIG. 3, a spring 62 interposed between the valve 48 and the piston 6 so that the valve closes on its seat 44 a little before the end of stroke of the piston in order to limit the impact of the end of stroke on the valve.
  • valve (42 or 48) instead of being directly carried by the piston, can be actuated by the latter, at the end of its travel, by a member, for example a rod control, carried by the piston.
  • the pipe 16 which is connected to the orifice 64 opening into the annular chamber 14 of the cylinder 4, must be a pipe of large section to allow rapid transfer of the between the two chambers 14 and 20.
  • Figure 5 is a sectional view of a preferred embodiment of the invention in which the cylinder 4 of the jack is a piece from foundry and not a steel tube.
  • This figure shows, in the left part, the piston 6 in the high position (engaged position) and, in the right part, the piston 6 in the low position (triggered position).
  • the piston 6 carries, on its underside, a valve frustoconical 42 which cooperates with a frustoconical seat 44 cut, on the edge of the feed / drain orifice 28 in the plug 46 forming the bottom of the cylinder.
  • FIG. 6 shows, in cross section along line 6-6 of FIG. 5, the transfer channel 16 ⁇ inside the foundry block 4.
  • the inner cylindrical surface 38 of the cylinder block need only undergo simple and economical machining, without running-in or polishing, since no lining on the piston 6 is liable to be damaged by imperfect machining of the cylinder.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Actuator (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Driving Mechanisms And Operating Circuits Of Arc-Extinguishing High-Tension Switches (AREA)
  • Control Of Fluid Gearings (AREA)
  • Retarders (AREA)
  • Fluid-Driven Valves (AREA)
  • Percussive Tools And Related Accessories (AREA)
  • Lift Valve (AREA)
  • Reciprocating Pumps (AREA)
  • Hydraulic Clutches, Magnetic Clutches, Fluid Clutches, And Fluid Joints (AREA)
  • Vehicle Body Suspensions (AREA)
  • Forklifts And Lifting Vehicles (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)

Abstract

Jack in which the annular chamber 14 of the cylinder 4 is always subjected to the high pressure of an accumulator 18. The piston 6 of the jack is free of any sealing lining in regard to the inner surface 38 of the cylinder and this piston mechanically actuates a valve 42 which sealingly closes off a seat 44 surrounding the feed/purge orifice 28 of the cylinder, at the bottom end of travel of the piston 6. The invention allows the cylinder 4 to be made in the form of a casting whose inner cylindrical surface 38 requires no accurate machining such as grinding or honing. <IMAGE>

Description

La présente invention concerne un vérin hydraulique différentiel pour la commande de disjoncteurs électriques, du type dans lequel la chambre annulaire du vérin, définie par la surface intérieure du cylindre du vérin et par la surface extérieure de la tige sortante du piston, est reliée en permanence à une source hydraulique haute-pression.The present invention relates to a differential hydraulic cylinder for controlling electric circuit breakers, of the type in which the annular chamber of the cylinder, defined by the interior surface of the cylinder of the cylinder and by the exterior surface of the outgoing rod of the piston, is permanently connected. to a high pressure hydraulic source.

La tige sortante du vérin est attelée au contact mobile du disjoncteur et un orifice d'alimentation /purge, ménagé dans le fond de la chambre principale du vérin, peut être raccordé sélectivement à ladite source haute pression (position "Alimentation") pour repousser le piston, ou bien à un réservoir basse pression (position "Purge") pour laisser le piston revenir à sa position initiale sous l'effet de la haute pression P régnant dans la chambre annulaire.The outgoing rod of the jack is coupled to the movable contact of the circuit breaker and a supply / bleed orifice, formed in the bottom of the main chamber of the jack, can be selectively connected to said high pressure source ("Supply" position) to repel the piston, or to a low pressure tank ("Purge" position) to let the piston return to its initial position under the effect of the high pressure P prevailing in the annular chamber.

La première manoeuvre fait sortir la tige de piston et amène le disjoncteur en position enclenchée ou fermée, tandis que la deuxième manoeuvre fait rentrer la tige dans le cylindre et amène le disjoncteur en position déclenchée ou ouverte.The first maneuver brings out the piston rod and brings the circuit breaker into the latched or closed position, while the second maneuver brings the rod back into the cylinder and brings the circuit breaker into the tripped or open position.

De telles commandes hydrauliques de disjoncteur, à vérin différentiel, sont bien connues et ont été décrites par exemple dans le brevet français N° 2.317.532 (ou brevet U.S. N° 4.026.523).Such hydraulic circuit breaker controls, with differential actuator, are well known and have been described for example in French patent No. 2,317,532 (or US patent No. 4,026,523).

La réalisation des vérins différentiels, pour cette application, présente des difficultés constructives, notamment du fait qu'ils doivent garantir une étanchéité permanente et absolue, pendant de très longues durées, malgré les pressions hydrauliques de service P très élevées, de l'ordre de 300 à 400 bar et des vitesses élevées de l'ordre de 10 à 15 mètres/seconde.Ces vérins doivent donc comporter au moins, comme il est représenté sur le brevet antérieur précité, une première garniture d'étanchéité au passage de la tige sortante à travers le fond du cylindre et une deuxième garniture d'étanchéité sur le piston.The construction of differential cylinders, for this application, presents constructive difficulties, in particular because they must guarantee a permanent and absolute tightness, for very long periods, despite the very high hydraulic operating pressures P, of the order of 300 to 400 bar and high speeds of the order of 10 to 15 meters / second. These jacks must therefore include at least, as shown in the aforementioned prior patent, a first seal at the passage of the outgoing rod through the bottom of the cylinder and a second seal on the piston.

La première de ces garnitures est relativement facile à réaliser pour obtenir une étanchéité absolue. En effet, cette garniture est fixe et il est facile d'obtenir une tige de piston rectifiée et polie qui n'use pas la garniture. D'autre part, la tige de piston, qui est pleine, ne varie pas de diamètre sous l'effet de la pression et la garniture n'est pratiquement pas soumise à des variations de pression puisque la chambre annulaire est toujours soumise à la pression permanente P fournie par un accumulateur oléo-pneumatique constituant la source de fluide hydraulique sous pression.The first of these fittings is relatively easy to produce in order to obtain an absolute seal. Indeed, this packing is fixed and it is easy to obtain a rectified and polished piston rod which does not wear the packing. On the other hand, the piston rod, which is full, does not vary in diameter under the effect of the pressure and the packing is practically not subjected to pressure variations since the annular chamber is always subjected to the pressure permanent P supplied by an oleopneumatic accumulator constituting the source of pressurized hydraulic fluid.

La deuxième de ces garnitures, c'est-à-dire celle assurant l'étanchéité entre le piston et le cylindre, doit supporter des conditions de fonctionnement beaucoup plus difficiles.The second of these seals, that is to say the one ensuring the seal between the piston and the cylinder, must withstand much more difficult operating conditions.

En effet cette garniture, montée sur le piston, est mobile et est soumis à de fortes accélérations et à des chocs du fait que les manoeuvres sont effectuées en des temps très courts, inférieurs à quelques 1/100e secondes ; elle est soumise à de fortes variations de pression entre les positions enclenchée et déclenchée ; le cylindre se dilate sous l'influence de la pression (de l'ordre de 300 à 400 bar) ; la surface intérieure du cylindre doit être parfaitement rectifiée et polie pour préserver l'intégrité de la garniture ; enfin, à la fin de course de déclenchement, la garniture peut être soumise à des surpressions considérables (plusieurs milliers de bar) qui sont prejudiciables à la tenue de la garniture si on ne prend pas certaines précautions, lesquelles conduisent à des complications structurelles.In fact, this seal, mounted on the piston, is movable and is subjected to strong accelerations and to shocks from the the fact that the maneuvers are carried out in very short times, less than a few 1 / 100th seconds; it is subjected to strong pressure variations between the engaged and triggered positions; the cylinder expands under the influence of pressure (of the order of 300 to 400 bar); the inner surface of the cylinder must be perfectly rectified and polished to preserve the integrity of the lining; finally, at the end of the triggering stroke, the lining can be subjected to considerable overpressures (several thousand bar) which are detrimental to the holding of the lining if certain precautions are not taken, which lead to structural complications.

Jusqu'à présent, les garnitures de piston n'ont pû être réalisées de façon satisfaisante que sous des formes relativement compliquées (au sujet desquelles de nombreux brevets ont été déposés) et coûteuses. De préférence, on utilise des garnitures dites "à ressort" qui sont formées d'un ou plusieurs anneaux de matière élastique maintenus comprimés par un ressort. Un exemple d'une telle garniture à ressort est représenté à la figure 2 du brevet antérieur précité. De toutes façons, de telles garnitures de piston ne peuvent coopérer qu'avec une surface de cylindre parfaitement polie.Up to now, the piston linings have only been able to be produced satisfactorily in relatively complicated and expensive forms (on which numerous patents have been filed). Preferably, so-called "spring" packings are used which are formed from one or more rings of elastic material kept compressed by a spring. An example of such a spring seal is shown in Figure 2 of the aforementioned prior patent. In any case, such piston linings can only cooperate with a perfectly polished cylinder surface.

Mis à part l'inconvénient de la difficulté de réalisation des garnitures de piston et de l'état de surface du cylindre, les vérins différentiels présentent encore l'inconvénient qu'on doit prévoir un conduit ou passage de grande section permettant un transfert rapide, à grand débit, entre la chambre principale et la chambre annulaire du vérin. En effet, les manoeuvres d'enclenchement ou de déclenchement du disjoncteur (c'est-à-dire la course aller ou la course retour du piston du vérin) doivent s'effectuer en un temps très court, de l'ordre de quelques centièmes de seconde, ce qui impose d'éviter tout freinage par une circulation ralentie d'huile.Aside from the drawback of the difficulty in producing the piston linings and of the surface condition of the cylinder, the differential cylinders still have the drawback that a duct or passage of large cross section must be provided for rapid transfer, at high speed, between the master bedroom and the annular chamber of the jack. Indeed, the circuit-breaker engagement or tripping maneuvers (that is to say the outward stroke or the return stroke of the cylinder piston) must be carried out in a very short time, of the order of a few hundredths of a second, which means that braking by a slower circulation of oil must be avoided.

Jusqu'à présent, on a le plus souvent réalisé ce passage de transfert de grande section au moyen d'une chemise entourant le cylindre du vérin, l'intervalle annulaire entre le vérin et la chemise constituant lui-même ce passage. Un exemple d'un tel mode de réalisation, qui complique encore la construction du vérin différentiel, est représenté sur la figure 3 du brevet antérieur précité.Up to now, this transfer passage of large section has most often been carried out by means of a jacket surrounding the cylinder of the jack, the annular gap between the jack and the jacket itself constituting this passage. An example of such an embodiment, which further complicates the construction of the differential cylinder, is shown in FIG. 3 of the aforementioned prior patent.

La présente invention a pour but de remédier aux inconvénients des vérins hydrauliques différentiels connus jusqu'à présent et de permettre une construction beaucoup plus simple et économique tout en assurant une fiabilité encore meilleure grâce à la réduction du nombre des constituants.The object of the present invention is to remedy the drawbacks of differential hydraulic cylinders known up to now and to allow much simpler and economical construction while ensuring even better reliability thanks to the reduction in the number of components.

Dans le texte qui suit on utilisera le terme de "course d'enclenchement" pour désigner le déplacement du piston depuis le fond de la chambre principale vers le fond de la chambre annulaire et le terme "course de déclenchement" pour désigner le déplacement de retour du piston en sens inverse.In the following text, the term "engagement stroke" will be used to designate the displacement of the piston from the bottom of the main chamber to the bottom of the annular chamber and the term "trigger stroke" to designate the return displacement. piston in reverse.

L'invention a pour objet un vérin hydraulique différentiel du type défini dans ce qui précède dans lequel le piston est dépourvu de garniture d'étanchéité coopérant avec la surface intérieure du cylindre du vérin, et dans lequel le piston est associé mécaniquement avec un clapet assurant la fermeture étanche permanente de l'orifice alimentation/purge de la chambre principale du vérin lorsque le piston est en position de fin de course de déclenchement.The subject of the invention is a differential hydraulic cylinder of the type defined in the foregoing in which the piston does not have a seal cooperating with the interior surface of the cylinder of the cylinder, and in which the piston is mechanically associated with a valve ensuring the permanent tight closure of the supply / bleed orifice of the main chamber of the jack when the piston is in the tripping end position.

Suivant cette disposition, la surface cylindrique extérieure du piston est en contact de glissement sensiblement direct, métal sur métal, avec la surface intérieure du cylindre. En l'absence de toute garniture d'étanchéité, il se produit bien entendu une fuite d'huile entre le piston et le cylindre, mais l'inventeur a découvert que cette fuite était négligeable pendant les mouvements du piston, dans un sens ou dans l'autre, qui ne durent que quelques centièmes de seconde.According to this arrangement, the external cylindrical surface of the piston is in substantially direct sliding contact, metal on metal, with the internal surface of the cylinder. In the absence of any seal, there is of course an oil leak between the piston and the cylinder, but the inventor has discovered that this leak was negligible during the movements of the piston, in one direction or in the other, which only last a few hundredths of a second.

En position "enclenchée", les pressions (P) sont identiques sur les deux faces du piston, donc il ne se produit pas de fuite de part et d'autre du piston.In the "engaged" position, the pressures (P) are identical on both sides of the piston, so there is no leakage on either side of the piston.

En position "déclenchée", la pression P régnant sur la face annulaire du piston gagne la face opposée du piston, du fait de la fuite existant entre le piston et le cylindre, mais elle est arrêtée ensuite par la fermeture étanche du clapet qui a été actionné par le piston à la fin de sa course de déclenchement. On évite ainsi tout écoulement permanent d'huile en position déclenchée, ce qui serait inacceptable sur une commande de disjoncteur.In the "triggered" position, the pressure P prevailing on the annular face of the piston gains the opposite face of the piston, due to the leak existing between the piston and the cylinder, but it is then stopped by the tight closure of the valve which has been actuated by the piston at the end of its trip. This avoids any permanent flow of oil in the tripped position, which would be unacceptable on a circuit breaker control.

Suivant une solution simple, le clapet est solidaire de la face opposée précitée du piston et le siège de clapet est formé à la périphérie de l'orifice alimentation/purge de la chambre principale.According to a simple solution, the valve is integral with the aforementioned opposite face of the piston and the valve seat is formed at the periphery of the supply / drain orifice of the main chamber.

Comme on le verra dans ce qui suit cette disposition du piston dépourvu de garniture procure d'autres avantages importants, notamment la possibilité de réaliser le cylindre sous la forme d'une pièce de fonderie ne nécessitant qu'un usinage simple, ce qui serait incompatible avec une garniture de piston. Par ailleurs il est possible de faire venir directement de fonderie le canal de transfert de forte section entre la chambre principale et la chambre annulaire du vérin, ce qui réduit considérablement le nombre des pièces constitutives du vérin.As will be seen in what follows, this arrangement of the piston devoid of packing provides other important advantages, in particular the possibility of producing the cylinder in the form of a foundry piece requiring only simple machining, which would be incompatible. with a piston seal. Furthermore, it is possible to bring directly from the foundry the transfer channel of large section between the main chamber and the annular chamber of the jack, which considerably reduces the number of constituent parts of the jack.

L'invention sera mieux comprise à la lecture de la description qui suit et à l'examen des dessins annexés sur lesquels :

  • La figure 1 est une représentation schématique d'un vérin différentiel suivant l'art antérieur et d'une commande hydraulique de disjoncteur connue dans laquelle est incorporé ce vérin.
  • La figure 2 est une vue en coupe d'un vérin différentiel selon la présente invention.
  • Les figures 3 et 4 sont des vues partielles montrant deux autres formes de réalisation du clapet de fermeture actionné par le piston.
  • La figure 5 est une vue en coupe axiale d'un vérin différentiel suivant l'invention avec bloc cylindre venu de fonderie.
  • La figure 6 est une vue en coupe suivant la ligne 6-6 de la figure 5.
The invention will be better understood on reading the description which follows and on examining the appended drawings in which:
  • Figure 1 is a schematic representation of a differential cylinder according to the prior art and a hydraulic circuit breaker known in which is incorporated this cylinder.
  • Figure 2 is a sectional view of a differential cylinder according to the present invention.
  • Figures 3 and 4 are partial views showing two other embodiments of the closing valve actuated by the piston.
  • Figure 5 is an axial sectional view of a differential cylinder according to the invention with cylinder block from the foundry.
  • Figure 6 is a sectional view along line 6-6 of Figure 5.

On a représenté sur la figure 1, pour situer l'art antérieur, le schéma hydraulique connu d'une commande de disjoncteur à vérin différentiel.There is shown in Figure 1, to locate the prior art, the known hydraulic diagram of a circuit breaker control differential actuator.

Cette commande comprend un vérin différentiel 2 comportant un cylindre 4, un piston 6, une tige de piston sortante 8 qui est attelée au contact mobile 10 d'un disjoncteur pour établir ou couper le circuit entre les contacts fixes 12-12ʹ du disjoncteur. La position représentée sur la figure 1 est la position déclenchée du disjoncteur (contacts ouverts), dans laquelle le piston 6 est proche de sa position basse dans le cylindre.This control comprises a differential cylinder 2 comprising a cylinder 4, a piston 6, an outgoing piston rod 8 which is coupled to the movable contact 10 of a circuit breaker to establish or cut the circuit between the fixed contacts 12-12ʹ of the circuit breaker. The position shown in Figure 1 is the tripped position of the circuit breaker (open contacts), in which the piston 6 is close to its low position in the cylinder.

La chambre annulaire 14 du vérin située au-dessus du piston 6 et entourant la tige de piston 8 est reliée en permanence, par une canalisation 15, à un accumulateur oléopneumatique haute-pression 18 (par exemple 300 à 400 bar), la pression dans cette chambre 14 tendant à ramener en permanence le disjoncteur en position déclenchée.The annular chamber 14 of the jack situated above the piston 6 and surrounding the piston rod 8 is permanently connected, by a pipe 15, to a high-pressure oleopneumatic accumulator 18 (for example 300 to 400 bar), the pressure in this chamber 14 tending to permanently return the circuit breaker to the tripped position.

Dans la chambre principale 20 du vérin est ménagé un passage ou orifice 28 qui peut être relié selectivement, par une canalisation d'alimentation/purge 22, sur laquelle est interposée une vanne à trois voies 24, soit, par l'intermédiaire d'une canalisation 22ʹ et d'une canalisation de transfert 16, à l'accumulateur 18 soit, par l'intermédiaire d'une canalisation 25, à une réservoir de purge à base pression 26 (position représentée sur la figure 1).In the main chamber 20 of the jack is formed a passage or orifice 28 which can be selectively connected, by a supply / purge pipe 22, on which is interposed a three-way valve 24, or, via a line 22ʹ and a transfer line 16, to the accumulator 18 or, via a line 25, to a pressure-based purge tank 26 (position shown in Figure 1).

Le fonctionnement est suffisamment connu pour qu'il suffise d'indiquer que la mise en position d'alimentation de la vanne 24 établit la HP dans la chambre 20 sur la grande surface du piston 6. Celui-ci est donc repoussé vers le haut à l'encontre de la force plus réduite exercée par le même HP sur sa surface annulaire, ce qui amène le disjoncteur en position enclenchée.The operation is sufficiently known to suffice to indicate that putting the supply position of the valve 24 establishes the HP in the chamber 20 on the large surface of the piston 6. The latter is therefore pushed up against the reduced force exerted by the same HP on its annular surface, which brings the circuit breaker in the engaged position.

Le déclenchement est obtenu par la mise en position purge de la vanne 24 (position de la figure 1). La HP régnant en permanence dans la chambre annulaire 13, repousse le piston 6 vers le bas, l'huile contenue dans la chambre principale 20 du vérin étant purgée rapidement à grand débit, grâce au fait que l'orifice alimentation/purge 28 et les organes hydrauliques associés 24-25 ont de fortes sections, ce qui permet d'effectuer la manoeuvre de déclenchement dans un temps très bref, de quelques centièmes de seconde.Triggering is obtained by placing the valve 24 in the purge position (position in Figure 1). The HP reigning permanently in the annular chamber 13, pushes the piston 6 downwards, the oil contained in the main chamber 20 of the jack being rapidly purged at high flow rate, thanks to the fact that the feed / purge orifice 28 and the 24-25 associated hydraulic members have large sections, which makes it possible to carry out the tripping operation in a very short time, of a few hundredths of a second.

Une commande hydraulique à vérin différentiel, pour disjoncteur, du type ci-dessus a été décrite par exemple dans le brevet français 2.317.532 (ou brevet US 4.026.523) et représentée à la figure 3 de ces documents.A hydraulic control with differential actuator, for circuit breaker, of the above type has been described for example in French patent 2,317,532 (or US patent 4,026,523) and represented in FIG. 3 of these documents.

Les vérins différentiels connus, comme celui représenté sur la figure 1, comportent une garniture d'étanchéité 30 au passage de la tige sortante 8 à travers le fond 32 du vérin et, également, une garniture d'étanchéité 34 sur le piston 6 pour assurer l'étanchéité entre le piston et la surface intérieure du cylindre 4. Cette garniture a été représentée sous la forme connue d'une garniture à ressort du genre représenté à la figu­re 2 du brevet antérieur précité et elle doit assurer l'étanchéité permanente de la chambre 14, sous la pression d'environ 300 à 400 bar, dans la position déclenchée représentée.Known differential cylinders, such as that shown in FIG. 1, include a seal 30 on the passage of the outgoing rod 8 through the bottom 32 of the cylinder and, also, a seal 34 on the piston 6 to ensure the seal between the piston and the interior surface of the cylinder 4. This seal has been shown in the known form of a spring seal of the kind shown in FIG. 2 of the aforementioned prior patent and it must ensure the permanent seal of the chamber 14, under the pressure of approximately 300 to 400 bar, in the triggered position shown.

La figure 2 annexée est une vue en coupe d'un vérin différentiel suivant l'invention, tous les éléments déjà décrits portant le même chiffre de référence.Figure 2 attached is a sectional view of a differential cylinder according to the invention, all the elements already described bearing the same reference number.

Comme on peut le voir une garniture d'étanchéité 30 est prévue au passage de la tige de piston 8 à travers le fond vi­sé 32 du cylindre 4, mais le piston 6 du vérin est dépourvu de toute garniture assurant l'étanchéité entre le piston 6, en métal, et le cylindre 4, en métal. Il en résulte que la surface cylindrique extérieure 36 du piston 6 coulisse sensiblement directement, métal sur métal, sur la surface intérieure 38 du cylindre 4, mais sans assurer l'étanchéité entre ces deux surfaces et sans que la surface 38 présente un usinage particulièrement précis.As can be seen, a seal 30 is provided for the passage of the piston rod 8 through the target bottom 32 of the cylinder 4, but the piston 6 of the jack is devoid of any seal ensuring the seal between the piston 6 , made of metal, and cylinder 4, made of metal. As a result, the outer cylindrical surface 36 of the piston 6 slides substantially directly, metal on metal, on the inner surface 38 of the cylinder 4, but without ensuring the seal between these two surfaces and without the surface 38 having a particularly precise machining. .

Le piston 6 porte, sous sa face inférieure 40, une partie en saillie formant un clapet tronc-conique 42 adapté à obturer, en fin de course de déclenchement (position représentée sur la figure 2) l'orifice d'alimentation/purge 28, lequel se trouve à la basse pression dans la position de fin de course de déclenchement représentée en traits pleins sur la figure 2.The piston 6 carries, under its underside 40, a projecting part forming a frusto-conical valve 42 adapted to close, at the end of the triggering stroke (position shown in FIG. 2), the supply / bleed orifice 28, which is at low pressure in the end-of-trip position shown in solid lines in FIG. 2.

Le clapet 42 peut s'adapter de façon étanche sur un siège de clapet tronconique 44 formé, surle bord de l'orifice 28, dans le fond vissé 46 du cylindre. Bien entenu, le siège de clapet 44 peut être constitué par une pièce rapportée , en matériau de dureté appropriée à celle du clapet, dans le fond du cylindre 46.The valve 42 can be fitted in a sealed manner on a frustoconical valve seat 44 formed, on the edge of the orifice 28, in the screwed bottom 46 of the cylinder. Properly maintained, the valve seat 44 can be constituted by an insert, of material of hardness suitable for that of the valve, in the bottom of the cylinder 46.

Dans la position enclenchée du disjoncteur, le passage alimentation/purge 28 du vérin est raccordé à l'accumulateur 18 par les canalisations 22-22ʹ-16 et par la valve 24 en position d'alimentation. Le piston 6 est donc repoussé vers le haut dans le cylindre et occupe la position représentée en traits interrompus sur la figure 2 où le piston est désigné par la référence 6ʹ et le clapet qu'il porte par la référence 42ʹ. La même pression P régnant sur les deux faces du piston la force F₁ exercée vers le haut sur le cylindre pour maintenir le disjoncteur fermé est :
    F₁ = P.S₁-P(S₁-s) = P.s
(S₁ étant la surface du piston et s la surface ou section de la tige 8) comme il est usuel sur un vérin différentiel.In the circuit-breaker on position, the supply / drain passage 28 of the jack is connected to the accumulator 18 by the lines 22-22ʹ-16 and by the valve 24 in position power supply. The piston 6 is therefore pushed up in the cylinder and occupies the position shown in broken lines in Figure 2 where the piston is designated by the reference 6ʹ and the valve it carries by the reference 42ʹ. The same pressure P prevailing on the two faces of the piston the force F₁ exerted upwards on the cylinder to keep the circuit breaker closed is:
F₁ = P.S₁-P (S₁-s) = Ps
( S ₁ being the surface of the piston and s the surface or section of the rod 8) as is usual on a differential cylinder.

Dans cette position, qui est la position normale de service du disjoncteur et qui peut durer des semaines, l'absence de garniture d'étanchéité sur le piston est sans inconvé­nient puisque la même pression P règne au-dessous du piston (dans la chambre principale 20) et au-dessus du piston (dans la chambre annulaire 14).In this position, which is the normal operating position of the circuit breaker and which can last for weeks, the absence of a seal on the piston is without drawback since the same pressure P prevails below the piston (in the main chamber 20) and above the piston (in the annular chamber 14).

Pour déclencher le disjoncteur, on met le passage alimentation/purge à la purge, au moyen de la valve 24 et le piston est repoussé vers le bas par la force F₂ = P(SD₁-s), la pression de purge P₀ sous le piston étant sensiblement la pression atmosphérique, au moins pendant le début de l'accélération du piston . En fin de course de déclenchement, position en traits pleins représentée sur la figure 2, le cla­pet 42 s'applique sur son siège 44 et ferme de façon étanche le passage 48, ce qui détermine en même temps une butée de fin de course du piston . La pression P régnant de façon permanente dans la chambre annulaire 14 ne peut donc s'échapper par le passage de purge et il n'y a donc pas de circulation permanente d'huile qui devrait être compensée par une pompe (non représentée) rechargeant l'accumulateur 18.To trip the circuit breaker, the feed / purge passage is put to the purge, by means of the valve 24 and the piston is pushed down by the force F₂ = P (SD₁-s), the purge pressure P₀ under the piston being substantially atmospheric pressure, at least during the start of acceleration of the piston. At the end of the triggering stroke, position in solid lines shown in FIG. 2, the valve 42 is applied on its seat 44 and closes the passage 48 in leaktight manner, which at the same time determines an end of stroke stop for the piston. . The pressure P permanently prevailing in the annular chamber 14 cannot therefore escape through the purge passage and there is therefore no permanent circulation of oil which should be compensated by a pump (not shown) recharging the accumulator 18.

La pression P régnant dans la chambre annulaire 14 peut tout au plus gagner, par la fuite existant entre le piston 6 et le cylindre, la face inférieure du piston 6, c'est-à-dire le volume, à ce moment réduit, de la chambre principale 20. Le piston 6 est donc soumis àla pression P à la fois sur sa surface annulaire supérieure "S₁-s" et sur sa surface annulaire inférieure "S₁-S₂", S₂ étant la section du clapet 42. Pour obtenir un effort d'application, suffisant pour assurer une bonne étanchéité du clapet 42 sur son siège, la section S₂ du clapet doit être notablement supérieure à la section s de la tige, par exemple de l'ordre de 50 %. De bons résultats ont été obtenus avec des valeurs comprises entre 25 % et 100 %.The pressure P prevailing in the annular chamber 14 can at most gain, by the leak existing between the piston 6 and the cylinder, the underside of the piston 6, that is to say the volume, at this reduced moment, of the main chamber 20. The piston 6 is therefore subjected to the pressure P both on its upper annular surface "S₁-s" and on its lower annular surface "S₁-S₂", S₂ being the section of the valve 42. To obtain a application force, sufficient to ensure good sealing of the valve 42 on its seat, the section S₂ of the valve must be significantly greater than the section s of the rod, for example of the order of 50%. Good results have been obtained with values between 25% and 100%.

Pendant les courses d'enclenchement ou de déclenchement du piston, qui ne durent que quelques centièmes de seconde, les fuites d'huile qui se produisent entre le piston et le cylindre ne représentent qu'un volume négligeable qui ne ralentit pas les manoeuvres du vérin.During the piston engagement or tripping strokes, which last only a few hundredths of a second, the oil leaks which occur between the piston and the cylinder represent only a negligible volume which does not slow down the actuations of the jack. .

On voit donc que la combinaison constituée par un piston dépourvu de garniture d'étanchéité et par un clapet, actionné mécaniquement par le piston, pour fermer l'orifice d'alimentation/purge en fin de course de déclenchement, permet de remplir toutes les conditions de fonctionnement et de sécurité d'une commande hydraulique de disjoncteur.It can therefore be seen that the combination of a piston without a gasket and a valve, actuated mechanically by the piston, to close the feed / bleed orifice at the end of the triggering stroke, makes it possible to meet all the operating and safety conditions of a hydraulic circuit breaker control.

Non seulement on élimine une garniture d'étanchéité de piston, de réalisation délicate, mais encore, comme on l'a indiqué à propos du cylindre 4 sur la figure 2 et comme on le verra plus en détail à propos des figures 5 et 6, on élimine tout usinage précis (rodage) de la surface intérieure 38 du cylindre.Not only is a piston seal, which is difficult to produce, eliminated, but also, as indicated in connection with the cylinder 4 in FIG. 2 and as will be seen in more detail in connection with FIGS. 5 and 6, any precise machining (lapping) of the interior surface 38 of the cylinder is eliminated.

On a représenté sur la figure 2 un clapet tronconique 42 lié au piston, mais on peut choisir tout autre type de clapet, par exemple un clapet du genre clapet à bille dans lequel l'organe obturateur est une sphère ou une portion de sphère 48 (figure 3) ou bien un clapet plan (figure 4) constitué par la face supérieure 50 du fond 46 du cylindre contre laquelle vient s'appliquer une lèvre circulaire 52 usinée dans la surface inférieure 54 du piston 6. Bien entendu, la disposition inverse, dans laquelle la lèvre d'étanchéité serait portée par la face supérieure 50 du fond du cylindre pourrait être aussi utilisée. On peut prévoir, pour coopérer avec la lèvre 52, une garniture annulaire 56 en matériau approprié.FIG. 2 shows a frustoconical valve 42 linked to the piston, but any other type of valve can be chosen, for example a valve of the ball valve type in which the shutter member is a sphere or a portion of a sphere 48 ( FIG. 3) or else a flat valve (FIG. 4) constituted by the upper face 50 of the bottom 46 of the cylinder against which a circular lip 52 machined is machined in the lower surface 54 of the piston 6. Of course, the reverse arrangement, in which the sealing lip is carried by the upper face 50 of the bottom of the cylinder could also be used. One can provide, to cooperate with the lip 52, an annular lining 56 of suitable material.

Il faut noter que, même avec un clapet plan, l'étanchéité à la fermeture du clapet est facile à réaliser grâce au fait que, dans la position basse de déclenchement du piston 6, le guidage de ce piston est assuré en deux points éloignés (d'une part, la garniture 30 de la tige 8 et, d'autre part, le contact entre le piston et le cylindre). Ainsi, le parallélisme de la face d'appui du clapet est reproduit avec fidélité à chaque manoeuvre.It should be noted that, even with a flat valve, sealing when the valve is closed is easy to achieve thanks to the fact that, in the low triggering position of the piston 6, the guidance of this piston is ensured at two distant points ( on the one hand, the lining 30 of the rod 8 and, on the other hand, the contact between the piston and the cylinder). Thus, the parallelism of the support face of the valve is reproduced with fidelity to each operation.

Le clapet peut être solidaire, ou faire partie intégrante, du piston 6, comme représenté sur les figures 2 et 4, ou bien il peut présenter un certain degré de liberté, comme il est représenté sur la figure 3 où le clapet hémisphérique 48 est engagé dans un logement 58, ménagé dans le piston 6, où il est retenu par une bague élastique 60. Einfin, on peut prévoir, comme sur la figure 3, un ressort 62 interposé entre le clapet 48 et le piston 6 de façon que le clapet se ferme sur son siège 44 un peu avant la fin de course du piston afin de limiter le choc de fin de course sur le clapet.The valve may be integral with, or form an integral part of, the piston 6, as shown in FIGS. 2 and 4, or else it may have a certain degree of freedom, as it is shown in FIG. 3 where the hemispherical valve 48 is engaged. in a housing 58, formed in the piston 6, where it is retained by an elastic ring 60. Finally, one can provide, as in FIG. 3, a spring 62 interposed between the valve 48 and the piston 6 so that the valve closes on its seat 44 a little before the end of stroke of the piston in order to limit the impact of the end of stroke on the valve.

Enfin, suivant une autre variante, non représentée, le clapet (42 ou 48), au lieu d'être directement porté par le piston, peut être actionné par ce dernier, à sa fin de course, par un organe, par exemple une tige de commande, porté par le piston.Finally, according to another variant, not shown, the valve (42 or 48), instead of being directly carried by the piston, can be actuated by the latter, at the end of its travel, by a member, for example a rod control, carried by the piston.

Il faut rappeler ici que, sur le schéma de la figure 2, la canalisation 16, qui est raccordée à l'orifice 64 débouchant dans la chambre annulaire 14 du cylindre 4, doit être une canalisation de forte section pour permettre un transfert rapide de l'huile entre les deux chambres 14 et 20.It should be recalled here that, in the diagram in Figure 2, the pipe 16, which is connected to the orifice 64 opening into the annular chamber 14 of the cylinder 4, must be a pipe of large section to allow rapid transfer of the between the two chambers 14 and 20.

La figure 5 est une vue en coupe d'un mode de réalisation préféré de l'invention dans lequel le cylindre 4 du vérin est une pièce venue de fonderie et non pas un tube d'acier.Figure 5 is a sectional view of a preferred embodiment of the invention in which the cylinder 4 of the jack is a piece from foundry and not a steel tube.

Sur cette figure on a représenté, dans la partie gauche, le piston 6 en position haute (position enclenchée) et, dans la partie droite, le piston 6 en position basse (position déclenchée). Le piston 6 porte, sur sa face inférieure, un clapet tronconique 42 qui coopère avec un siège tronconique 44 taillé, sur le bord de l'orifice alimentation/purge 28 dans le bouchon 46 formant le fond du cylindre.This figure shows, in the left part, the piston 6 in the high position (engaged position) and, in the right part, the piston 6 in the low position (triggered position). The piston 6 carries, on its underside, a valve frustoconical 42 which cooperates with a frustoconical seat 44 cut, on the edge of the feed / drain orifice 28 in the plug 46 forming the bottom of the cylinder.

Dans la pièce de fonte formant le cylindre 8, on fait venir de fonderie le canal de transfert 16ʹ, de forte section, qui n'a donc plus besoin d'être raccordé à l'orifice 64 de la chambre annulaire 14 en tant que constituant séparé. La figure 6 montre, en coupe transversale suivant la ligne 6-6 de la figu­re 5, le canal de transfert 16ʹ à l'intérieur du bloc de fonde­rie 4.In the casting part forming the cylinder 8, the transfer channel 16ʹ, of large section, is brought from the foundry, which therefore no longer needs to be connected to the orifice 64 of the annular chamber 14 as a constituent separate. FIG. 6 shows, in cross section along line 6-6 of FIG. 5, the transfer channel 16ʹ inside the foundry block 4.

La surface cylindrique intérieur 38 du bloc cylindre n'a besoin de subir qu'un usinage simple et économique, sans rodage ni polissage, puisqu'aucune garniture surle piston 6 ne risque d'être endommagée par un usinage imparfait du cylindre.The inner cylindrical surface 38 of the cylinder block need only undergo simple and economical machining, without running-in or polishing, since no lining on the piston 6 is liable to be damaged by imperfect machining of the cylinder.

On arrive ainsi à une solution constructive beaucoup moins couteuse que celle des vérins différentiels connus jusqu'à présent, tout en conservant les qualités de sécurité et fiabilité exigées pour la commande des disjoncteurs électriques.We thus arrive at a constructive solution much less expensive than that of the differential cylinders known up to now, while retaining the safety and reliability qualities required for the control of electric circuit breakers.

Claims (10)

1. Vérin hydraulique différentiel, pour commande oléopneumatique de disjoncteur électrique qui comprend un cylindre (4), un piston (6) et une tige sortante de piston (8) définissant, dans le cylindre, une chambre annulaire (14) d'un côté du piston et une chambre principale (20) de l'autre côté du piston, ladite tige sortante (8) étant attelée au contact mobile (10) du disjoncteur, ladite cham­bre annulaire (14) étant reliée en permanence à une source (18) de fluide hydraulique haute pression et ladite chambre principale (20) comportant, dans le fond correspondant (46) du cylindre un orifice d'alimentation/purge (28) de ladite chambre (20), ledit vérin différentiel étant caractérisé en ce que :
      - la surface cylindrique extérieure (36) du piston (6) est sensiblement en contact de glissement direct non étanche, métal sur métal, avec la surface intérieure (38) du cylindre (4), ledit piston étant dépourvu de garniture d'étanchéité avec le cylindre;
- le piston est associé mécaniquement à un clapet (42) assurant la fermeture étanche de l'orifice (28) préci­té à la fin de la course de retour du piston (6) vers le fond (46) précité du cylindre;
- et le corps du cylindre (4) est réalisé sous la forme d'une pièce de fonderie.1. Differential hydraulic cylinder, for oleopneumatic control of electric circuit breaker which comprises a cylinder (4), a piston (6) and an outgoing piston rod (8) defining, in the cylinder, an annular chamber (14) on one side piston and a main chamber (20) on the other side of the piston, said outgoing rod (8) being coupled to the movable contact (10) of the circuit breaker, said annular chamber (14) being permanently connected to a source (18) of high pressure hydraulic fluid and said main chamber (20) comprising, in the corresponding bottom (46) of the cylinder a supply / bleed orifice (28) of said chamber (20), said differential cylinder being characterized in that:
- The external cylindrical surface (36) of the piston (6) is substantially in non-leaktight direct sliding contact, metal on metal, with the internal surface (38) of the cylinder (4), said piston being devoid of seal with the cylinder;
- The piston is mechanically associated with a valve (42) ensuring the tight closure of the aforementioned orifice (28) at the end of the return stroke of the piston (6) towards the aforementioned bottom (46) of the cylinder;
- And the cylinder body (4) is made in the form of a foundry piece. 2. Vérin hydraulique suivant la revendication 1, caractérisé en ce que la pièce de fonderie constituant le corps du cylindre comporte également, venue de fonderie, une canalisation de transfert (16ʹ), de grande section, débouchant dans la chambre annulaire (14) du vérin.2. Hydraulic cylinder according to claim 1, characterized in that the foundry piece constituting the cylinder body also comprises, coming from the foundry, a transfer pipe (16ʹ), of large section, opening into the annular chamber (14) of the cylinder. 3. Vérin suivant l'une des revendications 1 ou 2, caractérisé en ce que la surface intérieure (38) du bloc cylindre (4) venue de fonderie ne subit qu'un usinage simplifié, sans rodage ni polissage.3. Cylinder according to one of claims 1 or 2, characterized in that the inner surface (38) of the cylinder block (4) coming from the foundry undergoes only a simplified machining, without running-in or polishing. 4. Vérin suivant l'une des revendications précéden­tes caractérisé en ce que la surface S₂ du clapet (42) est de l'ordre de 50% supérieure à la section s de la tige (8) du piston (6).4. Cylinder according to one of the preceding claims, characterized in that the surface S₂ of the valve (42) is of the order of 50% greater than the section s of the rod (8) of the piston (6). 5. Vérin suivant l'une des revendications précéden­tes caractérisé en ce que le clapet (42 - 48 - 52) est por­té par le piston (6) est fait saillie en-dessous de la sur­face principale du piston tournée vers la chambre principa­le (20).5. Cylinder according to one of the preceding claims, characterized in that the valve (42 - 48 - 52) is carried by the piston (6) is protruded below the main surface of the piston facing the main chamber (20 ). 6. Vérin suivant l'une des revendications précéden­tes caractérisé en ce que le clapet (42-52) est solidaire du piston (6).6. Cylinder according to one of the preceding claims, characterized in that the valve (42-52) is integral with the piston (6). 7. Vérin suivant l'une des revendications précéden­tes caractérisé en ce que le clapet (42 - 48 - 52) coopére avec un siège prévu dans le fond (46) du cylindre autour du bord de l'orifice (28) d'alimentation/purge, ledit siè­ge constituant une butée de fin de course pour le piston (6).7. Cylinder according to one of the preceding claims, characterized in that the valve (42 - 48 - 52) cooperates with a seat provided in the bottom (46) of the cylinder around the edge of the orifice (28) supply / purge, said seat constituting an end of travel stop for the piston (6). 8. Vérin suivant l'une des revendications précéden­tes caractérisé en ce que le clapet (42) est un clapet tronconique qui coopère avec un siège tronconique (44).8. Cylinder according to one of the preceding claims, characterized in that the valve (42) is a frustoconical valve which cooperates with a frustoconical seat (44). 9. Vérin suivant l'une des revendications 1 à 5, caractérisé en ce que le clapet (48) est une pièce distincte du piston et est retenue dans un logement (58) ménagé dans le piston.9. Cylinder according to one of claims 1 to 5, characterized in that the valve (48) is a separate part of the piston and is retained in a housing (58) formed in the piston. 10. Vérin suivant la revendication 9, caractérisé en ce que des moyens élastiques (62) sont interposés entre le clapet (48) et le piston (6).10. Cylinder according to claim 9, characterized in that elastic means (62) are interposed between the valve (48) and the piston (6).
EP88400574A 1987-03-25 1988-03-11 Differential hydraulic jack for operating electric breakers Expired - Lifetime EP0284482B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT88400574T ATE71471T1 (en) 1987-03-25 1988-03-11 DIFFERENTIAL HYDRAULIC POWER CYLINDER FOR CONTROL OF CIRCUIT BREAKER.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8704134 1987-03-25
FR8704134A FR2613122B1 (en) 1987-03-25 1987-03-25 DIFFERENTIAL HYDRAULIC CYLINDER FOR THE CONTROL OF ELECTRIC CIRCUIT BREAKERS

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EP0284482A1 true EP0284482A1 (en) 1988-09-28
EP0284482B1 EP0284482B1 (en) 1992-01-08

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EP88400574A Expired - Lifetime EP0284482B1 (en) 1987-03-25 1988-03-11 Differential hydraulic jack for operating electric breakers

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EP (1) EP0284482B1 (en)
JP (1) JP2593909B2 (en)
KR (1) KR920006522B1 (en)
CN (1) CN1008652B (en)
AT (1) ATE71471T1 (en)
AU (1) AU599217B2 (en)
BR (1) BR8801365A (en)
CA (1) CA1319728C (en)
DE (1) DE3867514D1 (en)
ES (1) ES2028314T3 (en)
FI (1) FI881400A (en)
FR (1) FR2613122B1 (en)
HU (1) HU204328B (en)
IN (1) IN170378B (en)
SU (1) SU1644724A3 (en)
YU (1) YU47464B (en)
ZA (1) ZA881688B (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1378068A (en) * 1963-07-24 1964-11-13 Merlin Gerin Improvement in hydraulic control devices, in particular for electrical switches
FR1462924A (en) * 1965-01-29 1966-12-16 Siemens Ag Compressed gas electric switch incorporating a minimum pressure interlocking device
FR2317532A1 (en) * 1975-07-07 1977-02-04 Gratzmuller Jean Louis HYDRAULIC CYLINDER WITH BUILT-IN SHOCK ABSORBER WITH DAMPER CHAMBER SUPPLY
EP0250619A1 (en) * 1986-05-27 1988-01-07 Mitsubishi Denki Kabushiki Kaisha Hydraulic operating apparatus

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1070266B (en) * 1958-06-04
FR1312751A (en) * 1961-01-24 1962-12-21 Coq Nv Improvements made to electrical switches with pneumatic current break
US3155009A (en) * 1961-08-03 1964-11-03 Gen Dynamics Corp High energy actuator apparatus
US4166937A (en) * 1978-05-18 1979-09-04 General Electric Company Hydraulically-activated operating system for an electric circuit breaker
JPS5598464U (en) * 1978-12-27 1980-07-09
JPS5693227A (en) * 1979-12-27 1981-07-28 Hitachi Ltd Hydraulic driving unit
JPS56153627A (en) * 1980-04-28 1981-11-27 Meidensha Electric Mfg Co Ltd Oil pressure operating device
JPS59109044U (en) * 1983-01-12 1984-07-23 株式会社東芝 Hydraulic pressure operating device for breaker
JPS61161627A (en) * 1985-01-08 1986-07-22 三菱電機株式会社 Hydraulic type operator
JPH0795416B2 (en) * 1986-02-26 1995-10-11 株式会社東芝 Hydraulic operating device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1378068A (en) * 1963-07-24 1964-11-13 Merlin Gerin Improvement in hydraulic control devices, in particular for electrical switches
FR1462924A (en) * 1965-01-29 1966-12-16 Siemens Ag Compressed gas electric switch incorporating a minimum pressure interlocking device
FR2317532A1 (en) * 1975-07-07 1977-02-04 Gratzmuller Jean Louis HYDRAULIC CYLINDER WITH BUILT-IN SHOCK ABSORBER WITH DAMPER CHAMBER SUPPLY
EP0250619A1 (en) * 1986-05-27 1988-01-07 Mitsubishi Denki Kabushiki Kaisha Hydraulic operating apparatus

Also Published As

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FI881400A (en) 1988-09-26
FR2613122A1 (en) 1988-09-30
AU599217B2 (en) 1990-07-12
BR8801365A (en) 1988-11-01
CN1008652B (en) 1990-07-04
JPS63254623A (en) 1988-10-21
CN88101589A (en) 1988-10-12
FR2613122B1 (en) 1989-06-23
YU55288A (en) 1990-04-30
FI881400A0 (en) 1988-03-24
JP2593909B2 (en) 1997-03-26
ZA881688B (en) 1988-09-06
CA1319728C (en) 1993-06-29
YU47464B (en) 1995-10-03
DE3867514D1 (en) 1992-02-20
SU1644724A3 (en) 1991-04-23
ES2028314T3 (en) 1992-07-01
IN170378B (en) 1992-03-21
EP0284482B1 (en) 1992-01-08
HUT48331A (en) 1989-05-29
KR880011481A (en) 1988-10-28
AU1351588A (en) 1988-09-29
KR920006522B1 (en) 1992-08-07
HU204328B (en) 1991-12-30
ATE71471T1 (en) 1992-01-15

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