EP0172080B1 - Polarised electromagnet with three positions and control circuit - Google Patents

Polarised electromagnet with three positions and control circuit Download PDF

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Publication number
EP0172080B1
EP0172080B1 EP85401463A EP85401463A EP0172080B1 EP 0172080 B1 EP0172080 B1 EP 0172080B1 EP 85401463 A EP85401463 A EP 85401463A EP 85401463 A EP85401463 A EP 85401463A EP 0172080 B1 EP0172080 B1 EP 0172080B1
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EP
European Patent Office
Prior art keywords
coil
winding
electromagnet
air
gaps
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Expired
Application number
EP85401463A
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German (de)
French (fr)
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EP0172080A1 (en
Inventor
Gérard Koehler
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Telemecanique SA
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La Telemecanique Electrique SA
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Publication of EP0172080A1 publication Critical patent/EP0172080A1/en
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H51/00—Electromagnetic relays
    • H01H51/22—Polarised relays
    • H01H51/2209—Polarised relays with rectilinearly movable armature
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H51/00—Electromagnetic relays
    • H01H51/22—Polarised relays
    • H01H51/2209—Polarised relays with rectilinearly movable armature
    • H01H2051/2218—Polarised relays with rectilinearly movable armature having at least one movable permanent magnet
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H51/00—Electromagnetic relays
    • H01H51/005—Inversing contactors

Definitions

  • the present invention relates to a three-state electromagnet.
  • the present invention also relates to a circuit for its control.
  • Three-state electromagnets are useful, for example, for controlling a device between a rest state and two different operating states.
  • such an electromagnet can be mounted in a contactor making it possible to put a three-phase motor in forward, in reverse or in standstill.
  • a contactor comprises contacts of the reversing type capable of also taking an intermediate position between the two extreme positions. To avoid a short circuit of the source during the duration of the electric arcs on the contacts, it is necessary to avoid that the inversion of the contacts is too fast.
  • this known contactor is tristable.
  • use with monostable contactors is more frequent.
  • to leave an extreme position it is necessary to excite the coil in a direction opposite to that which served for the preceding excitation.
  • the armature risks exceeding the stable central position and going to the other extreme position. Instead of stopping, the controlled motor will run in reverse, which can be very dangerous.
  • the strength of the magnets varies with temperature and the strength of the contact springs decreases with contact wear.
  • EP-A-86 121 there is known an electromagnet having two assemblies provided with permanent magnets which are movable relative to each other by defining between them four air gaps.
  • the permanent magnets are in series with each other at one of the extreme positions which is therefore stable, and in opposition with each other at the other extreme position which is therefore unstable.
  • Such an electromagnet is monostable without artifice but if it is used in a contactor, it can only put the power contacts in two different positions, not three.
  • FR-A-2 554 957 (not published on the priority date of this application) describes an electromagnet of the same type (two positions, two permanent magnets), but bistable.
  • US-A-2 872 546 is a three-position monostable electromagnet in which a permanent rotating magnet is mounted between two fixed magnets connected by their middle each to one end of a fixed yoke.
  • the mobile magnet takes an intermediate position in which its North pole is equidistant from the North poles of the fixed magnets and its South pole equidistant from the South poles of the fixed magnets.
  • the movable magnet pivots in one direction or the other.
  • this electromagnet is not very effective because the coils act practically only to suppress certain repulsion forces and to let others remain.
  • the object of the invention is thus to propose an electromagnet with three positions, which develops significant magnetic forces in the "working" positions and which is not likely to pass from one extreme position to the other when it has only been commanded to return to the central or intermediate position, and which, without costly modification such as the increase in the travel or the inertia of the moving assembly, is not likely to pass too quickly from an extreme position to the other by creating a risk of short circuit.
  • the invention thus relates to a polarized electromagnet comprising a magnetic circuit and at least one excitation coil surrounding a part of the magnetic circuit; the latter is constituted by two crews each comprising at least one permanent magnet provided on its pole faces with pole pieces, the crews being movable relative to each other between two extreme positions; the pole pieces of one crew form with the pole pieces of the other crew two opposing pairs of variable gaps, the gaps of one pair closing when the gaps of the other pair open due to the relative movement of the crews whose direction is determined by the state of excitation of the coil.
  • each air gap has facing faces connected to the polar faces of permanent magnets of the same magnetic polarity.
  • each air gap has facing faces connected to polar faces of permanent magnets of the same magnetic polarity and the sizes of the permanent magnets are chosen on the one hand appreciably canceling, in the absence of excitation of the coil, the flow which passes through the closed air gaps, thus making it possible to bring the position of the crews to an intermediate position between the two
  • the air gaps are formed by ends of the pole pieces and each of these ends belongs to only one air gap.
  • the return means envisaged here as a possible only have a supporting role bringing into play low forces compared to the electromagnetic forces and possibly ensuring better resistance to vibrations in the intermediate position, the essential being to remove the electromagnetic force of attraction. They are therefore not recall means providing significant efforts that more than counterbalance the force of the permanent magnet, at the risk of remanance.
  • control circuit for the above electromagnet comprises, for at least one of the windings of the coil, an assembly comprising a pluggable capacitor in parallel with the winding, a resistor connected in series with this winding, a discharge resistor connectable in parallel with the capacitor, and a switching means movable between a first position in which a supply line of the winding and the capacitor are connected to a source terminal while the discharge resistance is disconnected, and a second position in which the capacitor is in series with the discharge resistance while the winding supply line is open.
  • a contactor according to the invention allows for example a motor to change the direction of rotation without abruptness or risk of short circuit between phases.
  • the capacitor discharges into the discharge resistance.
  • the two windings can each be equipped with an aforementioned assembly, in which case the operation described above takes place each time that the excitation is passed from one winding to the other.
  • the electromagnet comprises a fixed element 1 and a mobile element 7.
  • the fixed element 1 comprises a permanent magnet 2 whose pole faces (N, S) are respectively provided with pole pieces 3 and 4.
  • a coil 5, wound on a coil carcass 6, surrounds the crew 1 in its central region where the magnet 2 is located, so that the field of the coil along an axis YY 'is perpendicular to the 'magnetization axis XX' of the permanent magnet 2.
  • the moving element 7 also comprises a permanent magnet 14 whose magnetization axis is parallel to XX ′ and whose pole faces (N, S) are provided with pole pieces 12 and 13 respectively.
  • the pole piece 3 has two ends 15, 16 emerging from the coil 5 and bent at right angles along the cheeks of the coil carcass 6.
  • the pole piece 12 has two ends 8, 9 bent at right angles so that they are parallel to the ends 15 and 16 and outside the latter.
  • a variable air gap E1 between the ends 15 and 8 and a variable air gap E2 between the ends 16 and 9 is thus determined between the crews.
  • the pole piece 13 has two ends 10, 11 bent at right angles so that they are parallel and outside the ends 8 and 9.
  • the pole piece 4 has two ends 17, 18 emerging from the coil 5 and bent at right angles so that they are parallel to the ends 10 and 11 and outside the latter.
  • a variable air gap E3 between the ends 10 and 17 and a variable air gap E4 between the ends 11 and 18 is thus determined between the crews.
  • the moving element 7 can move in translation in a direction parallel to the axis of the coil. It can be seen in FIG. 2 that this crew is guided by notches in the cheeks of the coil carcass 6.
  • the air gaps E 1 and E4 are closed by bringing their opposite faces together while the air gaps E2 and E3 are open.
  • the air gaps E2 and E3 are closed, E1 and E4 being open.
  • the two pairs of air gaps E1-E4 and E2-E3 therefore have antagonistic effects.
  • the polarities of the permanent magnets 2 and 14 are chosen so that the facing faces of each air gap are connected to the polar faces of permanent magnet of the same polarity, namely the polarity N for the air gaps E1 and E2 and the polarity S for the air gaps E3 and E4.
  • each end of the pole piece belongs to only one air gap, while for example in EP-A-86 121, certain ends of the pole pieces (9a and 9b) belong to two antagonistic air gaps.
  • the sizes of the permanent magnets are chosen so that no magnetic flux crosses a closed air gap in the absence of excitation of the coil 5. This prevents the extreme positions from being stable positions. We can even ensure that the permanent magnets see lower external reluctances when the moving element 7 is in an intermediate position substantially at the halfway point of the extreme positions, as in FIG. 1. For this, it may be advantageous to add permanent magnets near the air gaps, for example between the parallel ends 8 and 10 as well as 9 and 11.
  • the sizes of the magnets (mainly their thickness) must also be chosen according to the amperes of the coil so that the latter reinforce a direction of flow of the flux of the permanent magnet 2, by bypassing the permanent magnet 14 and ensuring a sufficient "working" force in the pair of closed airgaps, depending on the direction of excitation of the coil.
  • this electromagnet is therefore of the monostable type from a stable central position.
  • the direction of movement of the moving element towards one of the extreme positions depends on the direction of excitation of the coil, and the cutting of the latter causes the suppression of the electromagnetic working forces, at least in their major part, the return in the central position being possibly assisted by springs.
  • the labor forces can be significant because the entire flux of the permanent magnet 2 is directed by the coil 5 in closed air gaps, while for example that in US-A-2 872 546, the coils act practically only to suppress certain forces of repulsion and to let others remain.
  • the electromagnet provides sufficient working forces, without however having residual forces.
  • the fixed and movable parts can be swapped by sliding the crew 1 in the coil carcass 6 whose cheeks are close together. It is also possible to remove certain arched ends of pole pieces, such as 15 and 16 in order to have a bearing end of the pole piece.
  • the ends of the pole pieces can also be flat or bent into a bayonet, as in FIG. 6 of FR-A-2 554 957, with due respect for the magnetic polarities.
  • FIG. 4 shows the electromagnet 21 of FIGS. 1 and 2, the moving assembly of which is fixed to the moving part 22 of three power contacts 23 of the reversing type, that is to say that the part mobile 22 of each contact 23 connects two pairs of distinct fixed contacts according to the extreme position occupied by the mobile assembly 7.
  • the crew 7 is in the intermediate position and the moving parts 22 are also in an intermediate position in which no contact is made.
  • the contacts 23 are mounted between the terminals RST of a three-phase source and the terminals of a three-phase motor M according to a conventional arrangement such that the motor turns in one direction or the other depending on whether the contacts 23 are in a position or in the other.
  • the coil 5 comprises two coils 5a, 5b (shown diagrammatically) wound to generate flows of opposite directions when they are supplied and having a common end A3 connected to the negative terminal of a direct current source by means of an emergency stop button A.
  • the other two ends Aa, Ab of the coils 5a, 5b can be connected as desired to the positive terminal of said source by a supply line 24a, 24b respectively.
  • Line 24a associated with winding 5a carries the working contacts of a monostable manual switch Pa, the rest contacts of which are on line 24b. It also carries the working contacts of another monostable manual switch Pb.
  • the motor M rotates in one direction or the other. As soon as the button is released, the engine stops.
  • FIG. 5 constitutes an improvement on that of FIG. 4, associated with a contactor similar to that of FIG. 4 except that it comprises an additional change-over contact, referenced 23a, whose moving part 22 is integral with the moving parts. 22 of contacts 23.
  • the input terminal of each fixed contact of contact 23a is connected to the positive terminal of the source.
  • Each of the output terminals is connected to a respective line 26a or 26b.
  • Line 26a is connected to line 24a which passes through a rest contact of an inverter 27b of the switch Pb.
  • line 26b is connected to line 24b passing through a rest contact of an inverter 27a of the switch Pa.
  • the arrangement is such that the self-supply line 26a or 26b which is closed by the contact 23a is always that which supplies the winding 5a or 5b, the action of which keeps the moving parts 22 in the position they occupy.
  • the lines 24a and 24b are connected to the positive terminal of the source via a working contact of the inverters 27a and 27b respectively.
  • Each coil 5a or 5b is associated with an assembly comprising a capacitor Ca or Cb mounted between point A3 and the positive terminal of the source, in series with a working contact of a second inverter 28a or 28b of the inverter Pa or Pb respectively.
  • a discharge resistor ra or rb is mounted in series with a rest contact of the second inverter 28a or 28b.
  • a resistor R3 common to the two assemblies is mounted between the pint A3 and the stop button A.
  • each capacitor Ca or Cb is in a closed circuit on its discharge resistance ra or rb and therefore has no effect on the control.
  • the inverter 27b opens the self-supply circuit of the winding 5a. The same inverter closes the direct link between line 24b and the positive terminal of the source. At the same time, the inverter 28b puts the capacitor Cb in parallel with the winding 5b and switches off the resistor rb.
  • the winding 5a ceases its action and allows the mobile assembly to return to the intermediate position.
  • the mobile team does not go beyond.
  • the other winding 5b having been connected in parallel with the capacitor Cb and in series with the resistor R3, its voltage rise takes place with the time constant R3, Cb, for example 1s, preferably more than 0 , 2s. It is only after a certain delay that the magnetic force generated by the winding 5b is sufficient to move the moving element to its other extreme position, to the left, allowing the engine to start in the other direction.
  • FIG. 6 is analogous to that of FIG. 5 except that, to take advantage of the presence of the capacitors by allowing supply by alternating current, a half-wave rectifier diode da has been inserted between point A3 and resistance R3.
  • each winding 5a or 5b is mounted in parallel with a freewheeling diode da or db with which the winding 5a or 5b forms a closed circuit when the winding is disconnected, the diode then having for direction passing the normal direction. through the winding, as permitted by the diode d.
  • the resistor R3 avoids the use of winding wires that are too fine for a 220 V alternating voltage and the low power required to control the electromagnet avoids having a large resistor R3.
  • the components ra, rb, Ca, Cb and R3 and any diodes can easily be housed in a housing with the same profile as that of the contactor (snap-fastening on bar, similar terminals, etc.) - or in a housing snapped onto the body of the contactor as a classic additive.
  • the pushbuttons Pa and Pb can be replaced by a single set of change-over contacts, with or without self-supply, but retaining the time delay for reversing the directions of rotation of the controlled motor.
  • the electromagnet described can also be used in a 3-way solenoid valve.

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  • Physics & Mathematics (AREA)
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  • Electromagnets (AREA)
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Description

La présente invention concerne un électro-aimant à trois états.The present invention relates to a three-state electromagnet.

La présente invention concerne également un circuit pour sa commande.The present invention also relates to a circuit for its control.

Les électro-aimants à trois états sont utiles par exemple pour commander un appareil entre un état de repos et deux états de marche différents. Par exemple, un tel électro-aimant peut être monté dans un contacteur permettant de mettre un moteur triphasé, en marche avant, en marche arrière ou à l'arrêt. Un tel contacteur comprend des contacts du type inverseur susceptibles de prendre en outre une position intermédiaire entre les deux positions extrêmes. Pour éviter un court-circuit de la source pendant la durée des arcs électriques sur les contacts, il faut éviter que l'inversion des contacts ne soit trop rapide.Three-state electromagnets are useful, for example, for controlling a device between a rest state and two different operating states. For example, such an electromagnet can be mounted in a contactor making it possible to put a three-phase motor in forward, in reverse or in standstill. Such a contactor comprises contacts of the reversing type capable of also taking an intermediate position between the two extreme positions. To avoid a short circuit of the source during the duration of the electric arcs on the contacts, it is necessary to avoid that the inversion of the contacts is too fast.

On connaît d'après la DE-A-3 138 265 et le FR-A-2 532 107 un contacteur polarisé à trois positions stables, comprenant un électro-aimant de type bistable à aimant permanent et un ressort de rappel dont l'effet est nul en position centrale de l'armature avec une brusque variation dès que l'armature s'écarte de sa position centrale. L'aimant permanent assure la stabilité de chacune des positions extrêmes malgré l'effet contraire du ressort.We know from DE-A-3 138 265 and FR-A-2 532 107 a polarized contactor with three stable positions, comprising a bistable type electromagnet with permanent magnet and a return spring whose effect is zero in the central position of the armature with a sudden variation as soon as the armature deviates from its central position. The permanent magnet ensures the stability of each of the extreme positions despite the opposite effect of the spring.

Ainsi, ce contacteur connu est tristable. Cependant, les utilisations avec des contacteurs monosta- bles sont plus fréquentes. De plus, pour quitter une position extrême, il faut exciter la bobine dans un sens inverse de celui qui a servi à l'excitation précédente. Or à ce stade, l'armature risque de dépasser la position centrale stable er d'aller jusqu'à l'autre position extrême. Au lieu de s'arrêter, le moteur commandé va tourner en sens inverse, ce qui peut être très dangereux. On sait en effet qu'il est difficile de doser des ampèretours, à cause des écarts de tension et de résistance dûs à l'échauffement. De plus, la force des aimants varie avec la température et la force des ressorts des contacts diminue avec l'usure des contacts.Thus, this known contactor is tristable. However, use with monostable contactors is more frequent. In addition, to leave an extreme position, it is necessary to excite the coil in a direction opposite to that which served for the preceding excitation. However, at this stage, the armature risks exceeding the stable central position and going to the other extreme position. Instead of stopping, the controlled motor will run in reverse, which can be very dangerous. We know that it is difficult to measure amperes back, because of the voltage and resistance differences due to heating. In addition, the strength of the magnets varies with temperature and the strength of the contact springs decreases with contact wear.

Pour remédier à ce défaut, le document antérieur propose d'exciter simultanément les bobinages en sens inverse. Leur effet total n'est alors plus que celui résultant des fuites dues aux positions différentes des bobinages, ce qui conduit à une mauvaise efficacité. En outre, la commutation des bobinages est difficile à mettre en oeuvre. De plus, la création de la position centrale stable par un ressort est difficile à obtenir et nécessite des précautions de mise en oeuvre onéreuses. Voir par exemple le livre «La Télégraphie et le Télex» de D. FAUGERAS, Ed. Eyrolles 1962, page 194 - relais à trois positions.To remedy this defect, the prior document proposes to simultaneously excite the windings in the opposite direction. Their total effect is then only that resulting from leaks due to the different positions of the windings, which leads to poor efficiency. In addition, the switching of the windings is difficult to implement. In addition, the creation of a stable central position by a spring is difficult to obtain and requires costly implementation precautions. See for example the book "La Télégraphie et le Télex" by D. FAUGERAS, Ed. Eyrolles 1962, page 194 - three position relay.

Il est bien proposé dans l'un des documents cités un moyen de rendre le contacteur monostable mais ce moyen est insuffisant en pratique.It is indeed proposed in one of the cited documents a means of making the contactor monostable but this means is insufficient in practice.

On connaît par ailleurs d'après le EP-A-86 121 un électro-aimant ayant deux équipages munis d'aimants permanents et mobiles l'un par rapport à l'autre en définissant entre eux quatre entrefers. Les aimants permanents sont en série l'un avec l'autre à l'une des positions extrêmes qui est donc stable, et en opposition l'un avec l'autre à l'autre position extrême qui est donc instable. Un tel électro-aimant est bien monostable sans artifice mais s'il est utilisé dans un contacteur, il ne peut mettre les contacts de puissance que dans deux positions différentes, et non trois.Furthermore, from EP-A-86 121 there is known an electromagnet having two assemblies provided with permanent magnets which are movable relative to each other by defining between them four air gaps. The permanent magnets are in series with each other at one of the extreme positions which is therefore stable, and in opposition with each other at the other extreme position which is therefore unstable. Such an electromagnet is monostable without artifice but if it is used in a contactor, it can only put the power contacts in two different positions, not three.

Le FR-A-2 554 957 (non publié à la date de priorité de la présente demande) décrit un électro-aimant du même type (à deux positions, à deux aimants permanents), mais bistable.FR-A-2 554 957 (not published on the priority date of this application) describes an electromagnet of the same type (two positions, two permanent magnets), but bistable.

On connaît également d'après le US-A-2 872 546 un électro-aimant monostable trois positions dans lequel un aimant permanent rotatif est monté entre deux aimants fixes raccordés par leur milieu chacun à l'une des extrémités d'une culasse fixe. En l'absence d'excitation, l'aimant mobile prend une position intermédiaire dans laquelle son pôle Nord est à égale distance des pôles Nord des aimants fixes et son pôle Sud à égale distance des pôles Sud des aimants fixes. Selon le sens d'excitation d'une bobine entourant la culasse, l'aimant mobile pivote dans un sens ou dans l'autre. Cependant, cet électro-aimant est peu efficace car les bobines n'agissent pratiquement que pour supprimer certaines forces de répulsion et pour en laisser subsister d'autres.Also known from US-A-2 872 546 is a three-position monostable electromagnet in which a permanent rotating magnet is mounted between two fixed magnets connected by their middle each to one end of a fixed yoke. In the absence of excitation, the mobile magnet takes an intermediate position in which its North pole is equidistant from the North poles of the fixed magnets and its South pole equidistant from the South poles of the fixed magnets. Depending on the direction of excitation of a coil surrounding the cylinder head, the movable magnet pivots in one direction or the other. However, this electromagnet is not very effective because the coils act practically only to suppress certain repulsion forces and to let others remain.

Or on sait que les forces de répulsion sont plus faibles que des forces d'attraction dans des entrefers fermés.Now we know that the forces of repulsion are weaker than forces of attraction in closed air gaps.

Le but de l'invention est ainsi de proposer un électro-aimant à trois positions, qui développe des forces magnétiques importantes dans les positions «travail» et qui ne risque pas de passer d'une position extrême à l'autre lorsqu'il a seulement été commandé pour revenir en position centrale ou intermédiaire, et qui, sans modification coûteuse telle que l'augmentation de la course ou de l'inertie de l'équipage mobile, ne risque pas de passer trop rapidement d'une position extrême à l'autre en créant un risque de court-circuit.The object of the invention is thus to propose an electromagnet with three positions, which develops significant magnetic forces in the "working" positions and which is not likely to pass from one extreme position to the other when it has only been commanded to return to the central or intermediate position, and which, without costly modification such as the increase in the travel or the inertia of the moving assembly, is not likely to pass too quickly from an extreme position to the other by creating a risk of short circuit.

L'invention vise ainsi un électro-aimant polarisé comprenant un circuit magnétique et au moins une bobine d'excitation entourant une partie du circuit magnétique; ce dernier est constitué par deux équipages comprenant chacun au moins un aimant permanent muni sur ses faces polaires de pièces polaires, les équipages étant mobiles l'un par rapport à l'autre entre deux positions extrêmes; les pièces polaires d'un equipage forment avec les pièces polaires de l'autre équipage deux paires antagonistes d'entrefers variables, les entrefers d'une paire se refermant lorsque les entrefers de l'autre paire s'ouvrent en raison du mouvement relatif des équipages dont le sens est déterminé par l'état d'excitation de la bobine. Dans l'une des paires d'entrefers, chaque entrefer a des faces en regard reliées à des faces polaires d'aimants permanents d'une même polarité magnétique.The invention thus relates to a polarized electromagnet comprising a magnetic circuit and at least one excitation coil surrounding a part of the magnetic circuit; the latter is constituted by two crews each comprising at least one permanent magnet provided on its pole faces with pole pieces, the crews being movable relative to each other between two extreme positions; the pole pieces of one crew form with the pole pieces of the other crew two opposing pairs of variable gaps, the gaps of one pair closing when the gaps of the other pair open due to the relative movement of the crews whose direction is determined by the state of excitation of the coil. In one of the pairs of air gaps, each air gap has facing faces connected to the polar faces of permanent magnets of the same magnetic polarity.

Suivant l'invention, dans l'autre paire d'entrefers, également chaque entrefer a des faces en regard reliées à des faces polaires d'aimants permanents d'une même polarité magnétique et les tailles des aimants permanents sont choisies pour d'une part annuler sensiblement, en l'absence d'excitation de la bobine, le flux qui passe dans les entrefers fermés, permettant ainsi de ramener la position des équipages dans une position intermédiaire entre les deuxAccording to the invention, in the other pair of air gaps, also each air gap has facing faces connected to polar faces of permanent magnets of the same magnetic polarity and the sizes of the permanent magnets are chosen on the one hand appreciably canceling, in the absence of excitation of the coil, the flow which passes through the closed air gaps, thus making it possible to bring the position of the crews to an intermediate position between the two

positions extrêmes, et pour d'autre part assurer en présence de l'excitation une attraction vers l'une ou l'autre des positions extrêmes suivant le sens de l'excitation de la bobine.extreme positions, and for the other hand ensuring in the presence of the excitation an attraction towards one or the other of the extreme positions according to the direction of the excitation of the coil.

Dans une réalisation préférée de l'invention, les entrefers sont formés par des extrémités des pièces polaires et chacune de ces extrémités n'appartient qu'à un seul entrefer.In a preferred embodiment of the invention, the air gaps are formed by ends of the pole pieces and each of these ends belongs to only one air gap.

De la sorte, lorsque les équipages sont dans une position extrême l'un par rapport à l'autre et que l'alimentation est coupée, la force électromagnétique d'attraction est supprimée et il apparaît des forces de répulsion comme dans la position «travail» du contacteur décrit dans EP-A-86 121. Si la force des aimants permanents a été choisie suffisante par rapport à une rémanance éventuelle dans les entrefers fermés, ces forces de répulsion ramènent les deux équipages dans leur position relative intemédiaire. On peut aussi choisir des aimants plus faibles en liaison avec des moyens de rappel élastiques, par exemple l'élasticité des contacts de puissance si l'électro-aimant est employé dans un contacteur. Il faut bien comprendre que les moyens de rappel envisagés ici à titre éventuel n'ont qu'un rôle d'appoint mettant en jeu des efforts faibles par rapport aux forces électromagnétiques et assurant éventuellement une meilleure résistance aux vibrations en position intermédiaire, l'essentiel étant de supprimer la force électromagnétique d'attraction. Ils ne s'agit donc pas de moyens de rappel fournissant des efforts importants devant plus que contrebalancer la force de l'aimant permanent, sous risque de rémanance.In this way, when the crews are in an extreme position relative to each other and the supply is cut off, the electromagnetic force of attraction is suppressed and repulsion forces appear as in the "work" position. »Of the contactor described in EP-A-86 121. If the strength of the permanent magnets has been chosen to be sufficient with respect to a possible remanence in the closed air gaps, these repulsion forces bring the two crews back to their relative intermediate position. It is also possible to choose weaker magnets in connection with elastic return means, for example the elasticity of the power contacts if the electromagnet is used in a contactor. It should be understood that the return means envisaged here as a possible only have a supporting role bringing into play low forces compared to the electromagnetic forces and possibly ensuring better resistance to vibrations in the intermediate position, the essential being to remove the electromagnetic force of attraction. They are therefore not recall means providing significant efforts that more than counterbalance the force of the permanent magnet, at the risk of remanance.

Une fois décollés de leur position relative extrême, les équipages ne peuvent dépasser leur position relative intermédiaire car au-delà, il apparaît des forces symétriques de rappel. La position intermédiaire est donc stable. C'est dans cette position que chaque aimant «voit» la réluctance la plus faible du circuit magnétique qui lui est imposé.Once taken off from their extreme relative position, the crews cannot exceed their intermediate relative position because beyond this, symmetrical restoring forces appear. The intermediate position is therefore stable. It is in this position that each magnet "sees" the lowest reluctance of the magnetic circuit which is imposed on it.

Lorsqu'on applique une excitation d'un sens donné, l'un des équipages se déplace par rapport à l'autre vers une position extrême, sous l'effet de forces semblables à celles engendrées dans le contacteur selon EP -A-86 121. Les différences entre deux forces d'aimant étant stables dans le temps et indifférentes à la température, la position intermédiaire est définie avec précision. Elle peut être réglée par désaimantation sélective.When an excitation of a given direction is applied, one of the crews moves relative to the other towards an extreme position, under the effect of forces similar to those generated in the contactor according to EP -A-86 121 The differences between two magnet forces being stable over time and indifferent to temperature, the intermediate position is precisely defined. It can be adjusted by selective demagnetization.

Selon un autre aspect de l'invention, le circuit de commande pour l'électro-aimant ci-dessus est caractérisé en ce qu'il comprend, pour l'un au moins des bobinages de la bobine, un ensemble comprenant un condensateur branchable en parallèle avec le bobinage, une résistance branchée en série avec ce bobinage, une résistance de décharge branchable en parallèle, avec le condensateur, et un moyen de commutation mobile entre une première position dans laquelle une ligne d'alimentation du bobinage et le condensateur sont reliés à une borne de source tandis que la résistance de décharge est déconnectée, et une seconde position dans laquelle le condensateur est en série avec la résistance de décharge tandis que la ligne d'alimentation du bobinage est ouverte.According to another aspect of the invention, the control circuit for the above electromagnet is characterized in that it comprises, for at least one of the windings of the coil, an assembly comprising a pluggable capacitor in parallel with the winding, a resistor connected in series with this winding, a discharge resistor connectable in parallel with the capacitor, and a switching means movable between a first position in which a supply line of the winding and the capacitor are connected to a source terminal while the discharge resistance is disconnected, and a second position in which the capacitor is in series with the discharge resistance while the winding supply line is open.

Ainsi, pour faire passer l'armature d'une position extrême à l'autre, on commence par couper l'alimentation du bobinage en service et on met sous tension le bobinage équipé de l'ensemble précité; l'equipage mobile est ainsi rappelé en position intermédiaire. Mais dans un premier temps, il ne peut dépasser cette position. En effet, la tension aux bornes du bobinage en question croît au rythme de la charge du condensateur et ce n'est qu'après un certain délai ou temps d'arrêt que ladite tension suffit à pousser l'équipage mobile jusqu'à l'autre position extrême. Avec un tel circuit de commande, un contacteur selon l'invention permet par exemple à un moteur de changer de sens de rotation sans brusquerie ni risque de court-circuit entre phases. Quand on remet en service ledit autre bobinage, le condensateur se décharge dans la résistance de décharge. Les deux bobinages peuvent être équipés chacun d'un ensemble précité, auquel cas le fonctionnement exposé ci-dessus a lieu chaque fois que l'on fait passer l'excitation d'un bobinage à l'autre.Thus, in order to pass the armature from one extreme position to the other, one begins by cutting the supply of the winding in service and the winding equipped with the above-mentioned assembly is energized; the moving part is thus recalled to the intermediate position. But at first, it cannot go beyond this position. In fact, the voltage at the terminals of the winding in question increases at the rate of the charging of the capacitor and it is only after a certain delay or stopping time that said voltage is sufficient to push the moving assembly up to the another extreme position. With such a control circuit, a contactor according to the invention allows for example a motor to change the direction of rotation without abruptness or risk of short circuit between phases. When the other winding is put back into service, the capacitor discharges into the discharge resistance. The two windings can each be equipped with an aforementioned assembly, in which case the operation described above takes place each time that the excitation is passed from one winding to the other.

D'autres particularités et avantages de l'invention ressortiront encore de la description ci-après.Other features and advantages of the invention will emerge from the description below.

Aux dessins annexés, donnés à titre d'exemples non limitatifs:

  • la figure 1 est une vue en coupe suivant l'axe de la bobine d'un électro-aimant selon l'invention;
  • la figure 2 est une vue en coupe de l'électro-aimant de la figure 1, perpendiculairement à l'axe de la bobine;
  • la figure 3 est une vue en perspective et en coupe d'un autre agencement d'un électro-aimant suivant l'invention;
  • la figure 4 est un schéma de montage de l'électro-aimant des figures 1 à 3 dans un contacteur pour la commande avant-arrière-arrêt d'un moteur triphasé; et
  • les figures 5 et 6 montrent le contacteur des figures 1 à 3 respectivement associé à deux circuits de commande selon l'invention, pour la commande avant-arrière-arrêt d'un moteur triphasé.
In the appended drawings, given by way of nonlimiting examples:
  • Figure 1 is a sectional view along the axis of the coil of an electromagnet according to the invention;
  • Figure 2 is a sectional view of the electromagnet of Figure 1, perpendicular to the axis of the coil;
  • Figure 3 is a perspective view in section of another arrangement of an electromagnet according to the invention;
  • Figure 4 is a circuit diagram of the electromagnet of Figures 1 to 3 in a contactor for the front-rear-stop control of a three-phase motor; and
  • Figures 5 and 6 show the contactor of Figures 1 to 3 respectively associated with two control circuits according to the invention, for the front-rear-stop control of a three-phase motor.

Dans la réalisation des figures 1 et 2, l'électro-aimant comprend un équipage fixe 1 et un équipage mobile 7. L'équipage fixe 1 comprend un aimant permanent 2 dont les faces polaires (N, S) sont munies respectivement des pièces polaires 3 et 4. Une bobine 5, bobinée sur une carcasse de bobine 6, entoure l'équipage 1 dans sa région centrale où se trouve l'aimant 2, de manière que le champ de la bobine suivant un axe YY' soit perpendiculaire à l'axe d'aimantation XX' de l'aimant permanent 2.In the embodiment of FIGS. 1 and 2, the electromagnet comprises a fixed element 1 and a mobile element 7. The fixed element 1 comprises a permanent magnet 2 whose pole faces (N, S) are respectively provided with pole pieces 3 and 4. A coil 5, wound on a coil carcass 6, surrounds the crew 1 in its central region where the magnet 2 is located, so that the field of the coil along an axis YY 'is perpendicular to the 'magnetization axis XX' of the permanent magnet 2.

L'equipage mobile 7 comprend également un aimant permanent 14 dont l'axe d'aimantation est parallèle à XX' et dont les faces polaires (N, S) sont munies respectivement des pièces polaires 12 et 13.The moving element 7 also comprises a permanent magnet 14 whose magnetization axis is parallel to XX ′ and whose pole faces (N, S) are provided with pole pieces 12 and 13 respectively.

La pièce polaire 3 a deux extrémités 15, 16 émergeant de la bobine 5 et cambrées à angle droit le long des joues de la carcasse de bobine 6.The pole piece 3 has two ends 15, 16 emerging from the coil 5 and bent at right angles along the cheeks of the coil carcass 6.

La pièce polaire 12 a deux extrémités 8, 9 cambrées à angle droit de manière à ce qu'elles soient parallèles aux extrémités 15 et 16 et à l'extérieur de ces dernières. On détermine ainsi entre les équipages un entrefer variable E1 entre les extrémités 15 et 8 et un entrefer variable E2 entre les extrémités 16 et 9.The pole piece 12 has two ends 8, 9 bent at right angles so that they are parallel to the ends 15 and 16 and outside the latter. A variable air gap E1 between the ends 15 and 8 and a variable air gap E2 between the ends 16 and 9 is thus determined between the crews.

La pièce polaire 13 a deux extrémités 10, 11 cambrées à angle droit de manière à ce qu'elles soient parallèles et à l'extérieur des extrémités 8 et 9.The pole piece 13 has two ends 10, 11 bent at right angles so that they are parallel and outside the ends 8 and 9.

Enfin la pièce polaire 4 a deux extrémités 17, 18 émergeant de la bobine 5 et cambrées à angle droit de manière à ce qu'elles soient parallèles aux extrémités 10 et 11 et à l'extérieur de ces dernières. On détermine ainsi entre les équipages un entrefer variable E3 entre les extrémités 10 et 17 et un entrefer variable E4 entre les extrémités 11 et 18.Finally, the pole piece 4 has two ends 17, 18 emerging from the coil 5 and bent at right angles so that they are parallel to the ends 10 and 11 and outside the latter. A variable air gap E3 between the ends 10 and 17 and a variable air gap E4 between the ends 11 and 18 is thus determined between the crews.

L'équipage mobile 7 peut se déplacer par translation suivant une direction parallèle à l'axe de la bobine. On voit sur la figure 2 que cet équipage est guidé par des encoches dans des joues de la carcasse de bobine 6.The moving element 7 can move in translation in a direction parallel to the axis of the coil. It can be seen in FIG. 2 that this crew is guided by notches in the cheeks of the coil carcass 6.

Pour une première position extrême de l'équipage mobile 7, les entrefers E 1 et E4 sont fermés par rapprochement de leurs faces en regard tandis que les entrefers E2 et E3 sont ouverts. Pour l'autre position extrême, ce sont les entrefers E2 et E3 qui sont fermés, E1 et E4 étant ouverts.For a first extreme position of the mobile assembly 7, the air gaps E 1 and E4 are closed by bringing their opposite faces together while the air gaps E2 and E3 are open. For the other extreme position, the air gaps E2 and E3 are closed, E1 and E4 being open.

Les deux paires d'entrefers E1-E4 et E2-E3 ont donc des effets antagonistes.The two pairs of air gaps E1-E4 and E2-E3 therefore have antagonistic effects.

Les polarités des aimants permanents 2 et 14 sont choisies de façon que les faces en regard de chaque entrefer soient reliées à des faces polaires d'aimant permanent de même polarité, à savoir la polarité N pour les entrefers E1 et E2 et la polarité S pour les entrefers E3 et E4.The polarities of the permanent magnets 2 and 14 are chosen so that the facing faces of each air gap are connected to the polar faces of permanent magnet of the same polarity, namely the polarity N for the air gaps E1 and E2 and the polarity S for the air gaps E3 and E4.

Cette disposition est rendue possible par le fait que chaque extrémité de pièce polaire n'appartient qu'à un seul entrefer, alors que par exemple dans le EP-A-86 121, certaines extrémités des pièces polaires (9a et 9b) appartiennent à deux entrefers antagonistes.This arrangement is made possible by the fact that each end of the pole piece belongs to only one air gap, while for example in EP-A-86 121, certain ends of the pole pieces (9a and 9b) belong to two antagonistic air gaps.

Les tailles des aimants permanents (principalement leurs surfaces) sont choisies de sorte qu'aucun flux magnétique ne traverse un entrefer fermé en l'absence d'excitation de la bobine 5. On évite ainsi que les positions extrêmes ne soient des positions stables. On peut même faire en sorte que les aimants permanents voient des réluctances extérieures plus faibles lorsque l'équipage mobile 7 est dans une position intermédiaire sensiblement à mi-course des positions extrêmes, comme sur la figure 1 . Pour cela, il peut être avantageux de rajouter des aimants per- mantents près des entrefers par exemple entre les extrémités parallèles 8 et 10 ainsi que 9 et 11.The sizes of the permanent magnets (mainly their surfaces) are chosen so that no magnetic flux crosses a closed air gap in the absence of excitation of the coil 5. This prevents the extreme positions from being stable positions. We can even ensure that the permanent magnets see lower external reluctances when the moving element 7 is in an intermediate position substantially at the halfway point of the extreme positions, as in FIG. 1. For this, it may be advantageous to add permanent magnets near the air gaps, for example between the parallel ends 8 and 10 as well as 9 and 11.

Mais les tailles des aimants (principalement leur épaisseur) doivent aussi être choisies en fonction des ampèretours de la bobine pour que ces derniers renforcent un sens de passage du flux de l'aimant permanent 2, en contournant l'aimant permanent 14 et en assurant une force «travail» suffisante dans la paire d'entrefers fermés, suivant le sens d'excitation de la bobine.But the sizes of the magnets (mainly their thickness) must also be chosen according to the amperes of the coil so that the latter reinforce a direction of flow of the flux of the permanent magnet 2, by bypassing the permanent magnet 14 and ensuring a sufficient "working" force in the pair of closed airgaps, depending on the direction of excitation of the coil.

Pratiquement, compte tenu des dissymétries entre les deux entrefers d'une paire d'entrefers, il est difficile d'obtenir une force de répulsion suffisante, et la position centrale peut être assurée d'une manière classique par des ressorts antagonistes agissant dès que l'équipage mobile 7 s'écarte, dans un sens ou l'autre, de sa position centrale, en améliorant la résistance aux chocs.Practically, taking into account the asymmetries between the two air gaps of a pair of air gaps, it is difficult to obtain a sufficient repelling force, and the central position can be ensured in a conventional manner by opposing springs acting as soon as the movable assembly 7 deviates, in one direction or the other, from its central position, improving the impact resistance.

Pour augmenter la force «travail», il peut être avantageux d'augmenter la puissance de l'aimant permanent 2, quitte à avoir un faible flux dans les entrefers fermés après coupure de la bobine, la force rémanente correspondante étant facilement compensée par un ressort bandé en fin de course, cette force pouvant résulter en partie de la force de compression de contacts.To increase the "working" force, it may be advantageous to increase the power of the permanent magnet 2, even if this means having a low flux in the closed air gaps after cutting the coil, the corresponding remanent force being easily compensated by a spring. bandaged at the end of the stroke, this force may result in part from the contact compression force.

Le fonctionnement de cet électro-aimant est donc du type monostable à partir d'une position centrale stable. Le sens de déplacement de l'équipage mobile vers une des positions extrêmes dépend du sens de l'excitation de la bobine, et la coupure de cette dernière provoque la suppression des forces électromagnétiques de travail, au moins dans leur plus grande partie, le retour en position centrale étant éventuellement assisté par des ressorts. Les forces travail peuvent être importantes car tout le flux de l'aimant permanent 2 est aiguillé par la bobine 5 dans des entrefers fermés, alors par exemple que dans le US-A-2 872 546, les bobines n'agissent pratiquement que pour supprimer certaines forces de répulsion et pour en laisser subsister d'autres.The operation of this electromagnet is therefore of the monostable type from a stable central position. The direction of movement of the moving element towards one of the extreme positions depends on the direction of excitation of the coil, and the cutting of the latter causes the suppression of the electromagnetic working forces, at least in their major part, the return in the central position being possibly assisted by springs. The labor forces can be significant because the entire flux of the permanent magnet 2 is directed by the coil 5 in closed air gaps, while for example that in US-A-2 872 546, the coils act practically only to suppress certain forces of repulsion and to let others remain.

De plus, par l'adjonction de pièces polaires, l'électro-aimant fournit des forces travail suffisantes, sans toutefois avoir des forces rémanentes.In addition, by the addition of pole pieces, the electromagnet provides sufficient working forces, without however having residual forces.

On peut permuter les parties fixe et mobile en faisant coulisser l'équipage 1 dans la carcasse de bobine 6 dont les joues sont rapprochées. On peut aussi supprimer certaines extrémités cambrées de pièces polaires, telles que 15 et 16 pour avoir une portée en bout de la pièce polaire.The fixed and movable parts can be swapped by sliding the crew 1 in the coil carcass 6 whose cheeks are close together. It is also possible to remove certain arched ends of pole pieces, such as 15 and 16 in order to have a bearing end of the pole piece.

Au lieu de cambrer les extrémités des pièces polaires 3 et 4 d'un même côté de l'axe YY' de la bobine 5, on peut les cambrer de part et d'autre de cet axe, comme cela est représenté sur la figure 3. Sur cette figure, c'est l'équipage 1 qui est mobile en coulissant dans la carcasse de la bobine 6 et l'équipage 7 est dédoublé de part et d'autre de la bobine 5. (Seul l'aimant permanent 14a avec ses pièces polaires 12a-13a est visible).Instead of bending the ends of the pole pieces 3 and 4 on the same side of the axis YY 'of the coil 5, they can be bent on either side of this axis, as shown in FIG. 3 In this figure, it is the crew 1 which is movable by sliding in the carcass of the coil 6 and the crew 7 is split on either side of the coil 5. (Only the permanent magnet 14a with its pole pieces 12a-13a is visible).

Au lieu d'être cambrées à angle droit, les extrémités des pièces polaires peuvent aussi être planes ou cambrées en bayonnette, comme sur la figure 6 du FR-A-2 554 957, au respect des polarités magnétiques près.Instead of being bent at a right angle, the ends of the pole pieces can also be flat or bent into a bayonet, as in FIG. 6 of FR-A-2 554 957, with due respect for the magnetic polarities.

Enfin, au lieu d'avoir des fermetures d'entrefer par rapprochement de deux faces der surface constante, on peut avoir des entrefers à distance d'entrefer constante, qui se ferment par variation de la zone de recouvrement de deux faces en regard. Pour réaliser une telle disposition, il suffit de prévoir sur la figure 1 que l'équipage mobile 7 puisse pivoter autour de l'axe XX', les entrefers E1 à E4 ayant des surfaces cylindriques convenablement décalées angulaire- ment.Finally, instead of having air gap closings by bringing together two faces with constant surface, it is possible to have air gaps with constant air gap distance, which are closed by variation of the overlap area of two opposite faces. To make such an arrangement, it suffices to provide in FIG. 1 that the mobile assembly 7 can pivot around the axis XX ', the air gaps E1 to E4 having cylindrical surfaces suitably angularly offset.

On a représenté à la figure 4 l'électro-aimant 21 des figures 1 et 2 dont l'équipage mobile est fixé à la pièce mobile 22 de trois contacts de puissance 23 de type inverseur, c'est-à-dire que la pièce mobile 22 de chaque contact 23 raccorde deux paires de contacts fixes distinctes selon la position extrême occupée par l'équipage mobile 7.FIG. 4 shows the electromagnet 21 of FIGS. 1 and 2, the moving assembly of which is fixed to the moving part 22 of three power contacts 23 of the reversing type, that is to say that the part mobile 22 of each contact 23 connects two pairs of distinct fixed contacts according to the extreme position occupied by the mobile assembly 7.

Dans la situation représentée, l'équipage 7 est en position intermédiaire et les pièces mobiles 22 sont également dans une position intermédiaire dans laquelle aucun contact n'est établi.In the situation shown, the crew 7 is in the intermediate position and the moving parts 22 are also in an intermediate position in which no contact is made.

Les contacts 23 sont montés entre les bornes RST d'une source triphasée et les bornes d'un moteur triphasé M selon un montage classique tel que le mo- teurtourne dans un sens ou dans l'autre selon que les contacts 23 sont dans une position ou dans l'autre.The contacts 23 are mounted between the terminals RST of a three-phase source and the terminals of a three-phase motor M according to a conventional arrangement such that the motor turns in one direction or the other depending on whether the contacts 23 are in a position or in the other.

La bobine 5 comprend deux bobinages 5a, 5b (représentés schématiquement) bobinés pour générer des flux de sens contraires lorsqu'ils sont alimentés et ayant une extrémité commune A3 reliée à la borne négative d'une source de courant continu par l'intermédiaire d'un bouton d'arrêt d'urgence A.The coil 5 comprises two coils 5a, 5b (shown diagrammatically) wound to generate flows of opposite directions when they are supplied and having a common end A3 connected to the negative terminal of a direct current source by means of an emergency stop button A.

Les deux autres extrémités Aa, Ab des bobinages 5a, 5b sont reliables au choix à la borne positive de ladite source par une ligne d'alimentation 24a, 24b respectivement.The other two ends Aa, Ab of the coils 5a, 5b can be connected as desired to the positive terminal of said source by a supply line 24a, 24b respectively.

La ligne 24a associée à l'enroulement 5a porte les contacts travail d'un commutateur manuel monostable Pa dont les contacts repos sont sur la ligne 24b. Celle-ci porte en outre les contacts travail d'un autre commutateur manuel monostable Pb.Line 24a associated with winding 5a carries the working contacts of a monostable manual switch Pa, the rest contacts of which are on line 24b. It also carries the working contacts of another monostable manual switch Pb.

Au repos, aucun des bobinages 5a, 5b n'est alimenté, et le moteur M reste à l'arrêt.At rest, none of the windings 5a, 5b is supplied, and the motor M remains stopped.

Selon que l'on appuie sur un bouton ou sur l'autre Pa ou Pb, le moteur M tourne dans un sens ou dans l'autre. Dès qu'on relâche le bouton, le moteur s'arrête.Depending on whether a button or the other Pa or Pb is pressed, the motor M rotates in one direction or the other. As soon as the button is released, the engine stops.

Le montage de la figure 5 constitue un perfectionnement de celui de la figure 4, associé à un contacteur analogue à celui de la figure 4 excepté qu'il comporte un contact inverseur supplémentaire, référencé 23a, dont la pièce mobile 22 est solidaire des pièces mobiles 22 des contacts 23. La borne d'entrée de chaque contact fixe du contact 23a est raccordée à la borne positive de la source. Chacune des bornes de sortie est raccordée à une ligne respective 26a ou 26b. La ligne 26a est raccordée à la ligne 24a qui passe par un contact de repos d'un inverseur 27b du commutateur Pb. De même la ligne 26b est raccordée à la ligne 24b passant par un contact repos d'un inverseur 27a du commutateur Pa. Comme on peut le vérifier d'après les flèches a et b montrant respectivement dans quel sens les bobinages 5a et 5b sollicitent les pièces mobiles 22, l'arrangement est tel que la ligne d'auto-alimentation 26a ou 26b qui est fermée par le contact 23a est toujours celle qui alimente le bobinage 5a ou 5b dont l'action maintient les pièces mobiles 22 dans la position qu'elles occupent.The assembly of FIG. 5 constitutes an improvement on that of FIG. 4, associated with a contactor similar to that of FIG. 4 except that it comprises an additional change-over contact, referenced 23a, whose moving part 22 is integral with the moving parts. 22 of contacts 23. The input terminal of each fixed contact of contact 23a is connected to the positive terminal of the source. Each of the output terminals is connected to a respective line 26a or 26b. Line 26a is connected to line 24a which passes through a rest contact of an inverter 27b of the switch Pb. Likewise line 26b is connected to line 24b passing through a rest contact of an inverter 27a of the switch Pa. As can be checked from the arrows a and b respectively showing in which direction the windings 5a and 5b stress the moving parts 22, the arrangement is such that the self-supply line 26a or 26b which is closed by the contact 23a is always that which supplies the winding 5a or 5b, the action of which keeps the moving parts 22 in the position they occupy.

De plus, en parallèle avec le contact 23a, les lignes 24a et 24b sont raccordées à la borne positive de la source via un contact travail des inverseurs 27a et 27b respectivement.In addition, in parallel with the contact 23a, the lines 24a and 24b are connected to the positive terminal of the source via a working contact of the inverters 27a and 27b respectively.

A chaque bobinage 5a ou 5b, est associé un ensemble comprenant un condensateur Ca ou Cb monté entre le point A3 et la borne positive de la source, en série avec un contact travail d'un second inverseur 28a ou 28b de l'inverseur Pa ou Pb respectivement. En parallèle avec chaque condensateur Ca ou Cb, est montée une résistance de décharge ra ou rb en série avec un contact repos du second inverseur 28a ou 28b. Une résistance R3 commune aux deux ensembles est montée entre le pint A3 et le bouton d'arrêt A.Each coil 5a or 5b is associated with an assembly comprising a capacitor Ca or Cb mounted between point A3 and the positive terminal of the source, in series with a working contact of a second inverter 28a or 28b of the inverter Pa or Pb respectively. In parallel with each capacitor Ca or Cb, a discharge resistor ra or rb is mounted in series with a rest contact of the second inverter 28a or 28b. A resistor R3 common to the two assemblies is mounted between the pint A3 and the stop button A.

Le fonctionnement est le suivant:The operation is as follows:

Le moteur étant supposé en marche dans le sens déterminé par le bobinage 5a, l'équipage mobile du contacteur est en position extrême vers la droite (flèche a) et le bobinage 5a est auto-alimenté via le contact 23a et la ligne 26a, les boutons des commutateurs Pa ou Pb étant relâchés. Chaque condensateur Ca ou Cb est en circuit fermé sur sa résistance de décharge ra ou rb et n'a donc pas d'effet sur la commande.The motor being assumed to be running in the direction determined by the winding 5a, the moving element of the contactor is in the extreme position to the right (arrow a) and the winding 5a is self-powered via the contact 23a and the line 26a, the Pa or Pb switch buttons being released. Each capacitor Ca or Cb is in a closed circuit on its discharge resistance ra or rb and therefore has no effect on the control.

Pour changer de sens de rotation, on appuie sur le bouton Pb. Ceci a plusieurs effets. D'une part, l'inverseur 27b ouvre le circuit d'auto-alimentation du bobinage 5a. Le même inverseur ferme la liaison directe entre la ligne 24b et la borne positive de la source. En même temps, l'inverseur 28b met le condensateur Cb en parallèle avec l'enroulement 5b et met hors circuit la résistance rb.To change the direction of rotation, press the Pb button. This has several effects. On the one hand, the inverter 27b opens the self-supply circuit of the winding 5a. The same inverter closes the direct link between line 24b and the positive terminal of the source. At the same time, the inverter 28b puts the capacitor Cb in parallel with the winding 5b and switches off the resistor rb.

Dès que son circuit d'auto-alimentation est interrompu, le bobinage 5a cesse son action et permet le retour de l'équipage mobile en position intermédiaire. Dans un premier temps, l'équipage mobile ne va pas au-delà. En effet, l'autre bobinage 5b ayant été branché en parallèle avec le condensateur Cb et en série avec la résistance R3, sa montée en tension s'effectue avec la constante de temps R3, Cb, par exemple 1s, de préférence plus de 0,2s. Ce n'est qu'après un certain délai que la force magnétique engendrée par le bobinage 5b suffit à déplacer l'équipage mobile jusqu'à son autre position extrême, vers la gauche, permettant le démarrage du moteur dans l'autre sens.As soon as its self-supply circuit is interrupted, the winding 5a ceases its action and allows the mobile assembly to return to the intermediate position. At first, the mobile team does not go beyond. In fact, the other winding 5b having been connected in parallel with the capacitor Cb and in series with the resistor R3, its voltage rise takes place with the time constant R3, Cb, for example 1s, preferably more than 0 , 2s. It is only after a certain delay that the magnetic force generated by the winding 5b is sufficient to move the moving element to its other extreme position, to the left, allowing the engine to start in the other direction.

L'exemple de la figure 6 est analogue à celui de la figure 5 excepté que, pour profiter de la présence des condensateurs en permettant l'alimentation par du courant alternatif, une diode de redressement demi- alternance d a été intercalée entre le point A3 et la résistance R3. De plus, chaque enroulement 5a ou 5b est monté en parallèle avec une diode de roue libre da ou db avec laquelle l'enroulement 5a ou 5b forme un circuit fermé lorsque l'enroulement est déconnecté, la diode ayant alors pour sens passant le sens normal de passage dans le bobinage, tel qu'il est permis par la diode d.The example of FIG. 6 is analogous to that of FIG. 5 except that, to take advantage of the presence of the capacitors by allowing supply by alternating current, a half-wave rectifier diode da has been inserted between point A3 and resistance R3. In addition, each winding 5a or 5b is mounted in parallel with a freewheeling diode da or db with which the winding 5a or 5b forms a closed circuit when the winding is disconnected, the diode then having for direction passing the normal direction. through the winding, as permitted by the diode d.

La résistance R3 évite l'emploi de fils de bobinage trop fins pour le cas d'une tension de 220 V alternatif et la faible puissance nécessaire à la commande de l'électro-aimant évite d'avoir une résistance R3 de grande taille.The resistor R3 avoids the use of winding wires that are too fine for a 220 V alternating voltage and the low power required to control the electromagnet avoids having a large resistor R3.

Les composants ra, rb, Ca, Cb et R3 et les diodes éventuelles peuvent facilement être logés dans un boîtier de même profil que celui du contacteur (encliquetage sur barreau, bornes semblables etc) - ou dans un boîtier encliqueté sur le corps du contacteur comme un additif classique.The components ra, rb, Ca, Cb and R3 and any diodes can easily be housed in a housing with the same profile as that of the contactor (snap-fastening on bar, similar terminals, etc.) - or in a housing snapped onto the body of the contactor as a classic additive.

Dans le cas d'une commande automatique, les boutons poussoirs Pa et Pb peuvent être remplacés par un seul jeu de contacts inverseurs, avec ou sans auto-alimentation, mais en conservant la temporisation de l'inversion des sens de rotation du moteur commandé.In the case of automatic control, the pushbuttons Pa and Pb can be replaced by a single set of change-over contacts, with or without self-supply, but retaining the time delay for reversing the directions of rotation of the controlled motor.

L'électro-aimant décrit peut aussi être employé dans une électro-valve à 3 voies.The electromagnet described can also be used in a 3-way solenoid valve.

Claims (11)

1. A polarized electromagnet comprising at least one excitation coil (5) and a magnetic circuit constituted by two systems (1, 7) each comprising at least one permanent magnet (2, 14) provided with pole pieces (3, 4; 12, 13) on its pole faces, the coil (5) surrounding one of the systems in a region comprising the permanent magnet, said systems (1, 7) being capable of relative displacement between two end positions,the pole pieces (3, 4) of one system (1) being adapted to form with the pole pieces (12, 13) of the other system (7) two oppositely-acting pairs of variable air-gaps (E 1, E4; E2, E3), the air-gaps of one pair being adapted to close when the air-gaps of the other pair open by reason of the relative displacement of the systems in a direction which is determined by the state of excitation of the coil (5), the opposite faces of one pair of air-gaps (E1, E4) being joined to pole faces of permanent magnets having the same magnetic polarity, characterized in that also the opposite faces of the other pair of air-gaps (E2, E3) are joined to pole faces of permanent magnets having the same magnetic polarity, and in that the sizes of the permanent magnets (2,14) are chosen so as to have the effect, on the one hand, when no excitation is applied to the coil (5), of substantially reducing to zero the flux which passes through a closed air-gap and thus making it possible to restore the systems to an intermediate relative position between the two end positions and on the other hand, when excitation is applied to the coil (5), of producing an attraction towards either of the two end positions according to the direction of excitation of the coil (5).
2. An electromagnet according to claim 1, characterized in that the air-gaps (E 1, E2, E3, E4) are formed by end positions (8, 9, 10, 11, 15, 16, 17,
18) of the pole pieces (3, 4, 12, 13) and in that each pole-piece end portion forms part of only one air-gap (E1, E2, E3, E4).
3. An electromagnet according to claim 2, characterized in that the ends (8, 9, 10, 11, 15, 16, 17,18) of the pole pieces (3,4,12,13) are bent-back at right angles so as to be parallel to each other.
4. An electromagnet according to claim 3, characterized in that closing of the air-gaps (E1, E2, E3, E4) is obtained by moving the opposite air-gap surfaces towards each other, said surfaces being transverse to the axis (Y-Y') of the coil (5) whereby the relative movement of the systems (1, 7) is a movement of translation in a direction parallel to the axis (Y-Y') of the coil (5).
5. An electromagnet according to claim 4, characterized in that said electromagnet comprises resilient restoring means.
6. A contactor comprising an electromagnet according to claim 5 and power contacts (23) of the changeover type, the switching condition of said contacts being determined by the relative positions of the moving systems of the electromagnet, characterized in that the restoring means comprise the elasticity of the power contacts (23).
7. A control circuit for an electromagnet according to claim 5 or 6, wherein the coil (5) comprises two windings (5a, 5b) which are wound so as to generate fluxes of opposite directions, characterized in that said circuit comprises for at least one of the coil windings an assembly comprising a capacitor (Ca, Cb) connectable in parallel with the winding, a resistor (R3) connected in series with said winding, a discharge resistor (ra, rb) connectable in parallel with the capacitor (Ca, Cb) and a switching means (Pa, Pb) movable between a first position in which a supply line (24a, 24b) for the winding (5a, 5b) and the capacitor are connected to a source terminal whilst the discharge resistor is disconneted, and a second position in which the capacitor is in series with the discharge resistor whilst the winding supply line is open.
8. A control circuit according to claim 7, characterized in that said circuit comprises an assembly as mentioned above for each winding, the first position of each switching means being unstable and the second position being stable.
9. A control circuit according to claim 8, characterized in that, said circuit comprises means for connecting the windings to the source via a contact of the changeover type (23a) controlled by the relative position of the moving systems and, in the case of each winding (5a, 5b) via a contact (27a, 27b) which is closed in the quiescent state and forms part of the switching means (Pb, Pa) assigned to the other winding (5b, 5a) in order to provide a control of the self- supply type.
10. A control circuit according to one of claims 7-9 and connectable to an alternating-current supply source, characterized in that a half-wave rectifier diode (d 1) is mounted in series with the two windings (5a, 5b) and in that each winding (5a, 5b) is mounted in parallel with a free-wheel diode (d2, d3).
EP85401463A 1984-07-20 1985-07-17 Polarised electromagnet with three positions and control circuit Expired EP0172080B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8411517 1984-07-20
FR8411517A FR2568056B1 (en) 1984-07-20 1984-07-20 POLARIZED THREE-STATE ELECTROMAGNET AND CIRCUIT FOR ITS CONTROL

Publications (2)

Publication Number Publication Date
EP0172080A1 EP0172080A1 (en) 1986-02-19
EP0172080B1 true EP0172080B1 (en) 1988-06-01

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP85401463A Expired EP0172080B1 (en) 1984-07-20 1985-07-17 Polarised electromagnet with three positions and control circuit

Country Status (5)

Country Link
US (1) US4609899A (en)
EP (1) EP0172080B1 (en)
JP (1) JPS61114430A (en)
DE (1) DE3563144D1 (en)
FR (1) FR2568056B1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4223287C2 (en) * 1991-07-17 2002-10-31 Tyco Electronics Austria Gmbh Poled electromagnetic relay

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63164135A (en) * 1986-08-08 1988-07-07 山本　誠二 Driver for working piece
DE3743366A1 (en) * 1987-12-21 1989-07-06 Schmidt Manfred Thermal roller blind with lateral magnetic-strip guidance
US5091710A (en) * 1988-07-28 1992-02-25 Matsushita Electric Industrial Co., Ltd. Step linear actuator
US4995744A (en) * 1988-12-16 1991-02-26 International Business Machines Corporation Impact printer actuator using magnet and electromagnetic coil and method of manufacture
US5254925A (en) * 1992-01-31 1993-10-19 Flynn Bros., Inc. Permanent magnet control means
ES2040647B1 (en) * 1992-03-16 1997-04-16 Bernardos Salvador Estors TRIESTATED CONTACTOR DEVICE.
US6046660A (en) * 1999-04-07 2000-04-04 Gruner; Klaus A. Latching magnetic relay assembly with a linear motor
EP1180778B1 (en) * 2000-08-18 2007-11-07 Ranco Incorporated of Delaware Tristable relay
ATE555340T1 (en) * 2009-10-16 2012-05-15 Diener Prec Pumps Ltd ELECTRONIC ADAPTER FOR CONTROLLING BISTABLE VALVES
DE102012107922A1 (en) * 2012-08-28 2014-03-06 Eto Magnetic Gmbh Electromagnetic actuator device
RU2713393C2 (en) * 2015-08-28 2020-02-05 Машиненфабрик Райнхаузен Гмбх Switch under load for stepped switch under load and permanent main switch and disconnector therefor
EP3211653B1 (en) * 2016-02-23 2019-08-14 Tyco Electronics Componentes Electromecanicos Lda Electromagnetic relay for three switching positions

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2735045A (en) * 1952-03-20 1956-02-14 Savoie
US2872546A (en) * 1956-02-03 1959-02-03 Stuart K Babcock Self-centering relay
FR2222746A1 (en) * 1973-03-20 1974-10-18 Campot Etienne Extra flat relay for four pole magnetic cct - can be mono-, bi-, or tristable
FR2358006A1 (en) * 1976-07-09 1978-02-03 Manuf Fse App Electr DEVICE FORMING ELECTRO-MAGNET, SUCH AS THAT OF A RELAY
JPS5636109A (en) * 1979-08-31 1981-04-09 Matsushita Electric Works Ltd Monostable type polar electromagnet
DE3243266C2 (en) * 1981-04-30 1986-06-26 Sds Relais Ag Polarized relay
DE3138265C2 (en) * 1981-09-25 1986-10-16 Sds-Elektro Gmbh, 8024 Deisenhofen Electromagnetic switching device
FR2520152B1 (en) * 1982-01-20 1986-02-28 Telemecanique Electrique ELECTRO-MAGNET WITH MOBILE EQUIPMENT WITH PERMANENT MAGNET WITH MONOSTABLE OPERATION
FR2532107B1 (en) * 1982-08-17 1986-08-29 Sds Elektro Gmbh ELECTROMAGNETIC CONNECTION APPARATUS COMPRISING A MAGNETIC CONTROL AND A CONTACT APPARATUS MOUNTED ON THE SAME

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4223287C2 (en) * 1991-07-17 2002-10-31 Tyco Electronics Austria Gmbh Poled electromagnetic relay

Also Published As

Publication number Publication date
US4609899A (en) 1986-09-02
JPS61114430A (en) 1986-06-02
DE3563144D1 (en) 1988-07-07
FR2568056A1 (en) 1986-01-24
FR2568056B1 (en) 1987-01-23
EP0172080A1 (en) 1986-02-19

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