EP1047090B1 - Limiting circuit breaker comprising an auxiliary energy accumulator - Google Patents

Description

The invention relates to a low-voltage limiting circuit breaker, and more particularly to a high-voltage low-voltage limiting circuit breaker.

• un boîtier ;
• un mécanisme d'ouverture comportant au moins un accumulateur d'énergie ;
• un ou plusieurs pôles comportant chacun :
  • un organe de contact fixe par rapport au boîtier ;
  • une butée fixe par rapport au boîtier ;
  • un organe de contact mobile comportant :
    • un support mobile relativement au boîtier entre une position de fermeture et une position d'ouverture ;
    • au moins un doigt de contact mobile relativement au support entre une position non répulsée et une position répulsée ;
    • au moins un mécanisme bistable comportant un ressort disposé entre le support et le doigt de telle manière qu'il passe par un maximum d'énergie potentielle lorsque le doigt et le support sont situés dans une position de point mort relativement l'un à l'autre, qu'il tende à rappeler le doigt vers sa position répulsée lorsque le doigt est situé relativement au support entre sa position répulsée et la position de point mort, et qu'il tende à rappeler le doigt vers sa position non répulsée lorsque le doigt est situé relativement au support entre sa position non répulsée et la position de point mort ;
  la butée étant disposée de telle manière que lorsque le doigt est positionné dans sa position répulsée et que le support passe de sa position de fermeture à sa position d'ouverture, le doigt, une fois en contact avec la butée, reste en contact avec celle-ci jusqu'à ce que le support dépasse une position intermédiaire de basculement relativement au boîtier, correspondant à la position relative de point mort par rapport au doigt,

le mécanisme d'ouverture étant lié cinématiquement au support de manière à rappeler le support vers sa position d'ouverture lorsque le support se trouve dans sa position de fermeture.GB-A-1,564,412 discloses a high-voltage low-voltage limiting circuit breaker, comprising

• a housing ;
• an opening mechanism comprising at least one energy accumulator;
• one or more poles each comprising:
  • a contact member fixed relative to the housing;
  • a fixed stop relative to the housing;
  • a movable contact member comprising:
    • a movable support relative to the housing between a closed position and an open position;
    • at least one movable contact finger relative to the support between a non-repulsed position and a repulsed position;
    • at least one bistable mechanism comprising a spring disposed between the support and the finger such that it passes through a maximum of potential energy when the finger and the support are located in a neutral position relative to one another; other, that it tends to return the finger to its repulsed position when the finger is located relative to the support between its repulsed position and the neutral position, and that it tends to return the finger to its non-repulsed position when the finger is located relative to the support between its non-repulsed position and the neutral position;
  the stop being arranged in such a way that when the finger is positioned in its repulsed position and the support passes from its closed position to its open position, the finger, once in contact with the stop, remains in contact with that until the support exceeds an intermediate position of tilting relative to the housing, corresponding to the relative position of neutral position with respect to the finger,

the opening mechanism being kinematically connected to the support so as to return the support towards its open position when the support is in its closed position.

The spring of the bistable device has several functions. It is intended first to ensure a contact pressure between the fixed contact member and the contact finger when the circuit breaker is closed, which is relatively independent of the state of wear and manufacturing tolerances of the circuit breaker. This contact pressure is also decisive for the repulsion threshold beyond which the electromagnetic forces will cause the finger to its repulsed position. When the finger has pivoted beyond the dead point, the spring is also used to confirm the repulsion and / or to prevent a rebound of the finger, since it prohibits the return of the finger in non-repulsed position. Before being able to close the circuit-breaker again, it is therefore necessary to release the energy accumulator from the opening mechanism, which drives the bar and with it the support of the movable contact member in the open position, and which allows the finger to rotate in non-repulsed position by cooperation with the stop.

In such a device, the energy accumulator of the opening mechanism must overcome the resistance of the spring of the bistable device. However, this passage should preferably be made at the beginning of the opening stroke, in order to limit the size of the compartment of the circuit breaker where the contacts are located. The support must pivot itself quickly enough, at the passage of the intermediate tilting position, so that the restoring force of the spring of the bistable device does not give rise, after the passage of the dead point, to a significant approximation between the finger and the fixed contact.

Therefore, the spring of the opening mechanism must simultaneously accelerate the support and compress the spring of the bistable device. In energy terms, it must simultaneously supply the spring of the bistable device with the energy necessary for it to reach its state of maximum potential energy, and provide the support with the kinetic energy necessary for its rapid movement towards the open position. . Remember also that the spring of the opening mechanism must also ensure only the rapid opening of the circuit breaker in case of tripping over low overcurrent.

To reconcile these constraints, there is generally provided a powerful opening energy accumulator. However this solution is not without inconvenience, since the energy released during the opening must be dissipated in the opening limit stops, so that the power of the spring is decisive for the cost and bulk. circuit breaker. In addition, it is necessary to provide different opening mechanisms according to the number of poles of the circuit breaker. Remember that not only are monopolar, three-pole and four-pole circuit breakers, but also, for high ratings where each phase is connected to two poles in parallel or in series, hexapole or even octopole circuit breakers.

The dimensioning problem is even more complicated when identical mobile contact members using identical supports, fingers and bistable devices are intended to equip circuit breakers whose opening mechanisms are of a different nature. Indeed, it is desired to be able to equip a range of circuit breakers indifferently with a first type of mechanism in which the energy accumulator of the opening mechanism also releases the energy necessary to close the circuit breaker, and with a second type of mechanism, said OFO (for open, closed, open) in which a closing energy accumulator is armed independently of the position of the contacts and ensures the arming of the opening energy accumulator simultaneously during the closing. But the two types of mechanism have different opening kinematics. It is thus generally considered that, for a given opening energy - that is to say for a given opening spring - the OFO mechanism is slower at the beginning of the opening stroke and faster at the end of the race. 'opening.

The invention therefore aims to overcome the disadvantages of the state of the art, and in particular to allow the use of movable contact members with identical bistable mechanisms for limiting circuit breakers whose opening mechanisms have variable characteristics, particularly in opening race start. It also aims to allow a sizing of the opening mechanism of a limiter circuit breaker, independent of the number of poles. Another object of the invention is to make the acceleration at the beginning of the opening stroke of the support of a movable contact member relatively independent of the type of opening mechanism used. Another object of the invention is to limit the energy to be dissipated at the end of the opening stroke, without significantly increasing either the opening stroke or the overall size of the device. Another goal is to minimize the energy needed during opening.

According to the invention, these objectives are achieved by means of a circuit breaker of the above type, in which each pole furthermore comprises an auxiliary mechanism comprising one or more energy accumulators reminding the support towards its open position on all or part of the run of the support between its closed position and the intermediate tilting position, but no longer beyond the intermediate tilting position. It is then possible to adjust the acceleration at the start of the opening stroke by judiciously choosing the power of the second accumulator.

Preferably, the energy accumulator (s) of the auxiliary mechanism do not act on the support when it is between its intermediate position tilting and its open position. Beyond the tilting position, the support does not need a lot of energy to reach its open position, so that the contribution of the second battery is no longer necessary.

Alternatively, it is possible to provide an accumulator providing energy to the support over part of its stroke at least between the closed position and the intermediate tilting position, and storing energy on at least part of the race support between the intermediate position and the open position. This accumulator may for example comprise a spring whose rest position corresponds to the relative position of tilting, acting in compression below and in traction beyond. This further limits the energy remaining to be dissipated in the end stops of the opening mechanism at the end of the opening stroke.

Preferably, the energy accumulator (s) of the auxiliary mechanism of each pole are such that during the displacement of the movable support of the pole considered, they release an energy greater than or equal to that necessary to bring the bistable mechanism (s) of the pole considered up to to their maximum potential energy. This arrangement is particularly advantageous for a multipole circuit breaker having a control mechanism common to all the poles. Indeed, it is then even easier to size the opening spring independently of the number of poles, while limiting its power.

According to one embodiment, the circuit breaker further comprises hooking means. This arrangement promotes the transition from the intermediate position of tilting to the open position. It therefore makes it possible to limit the kinetic energy required for the passage of the intermediate tilting position. This therefore makes it possible to limit the power of the auxiliary mechanism and also limits the energy to be dissipated in the opening limit stops.

According to a preferred embodiment, the energy accumulator or accumulators of the auxiliary mechanism each comprise a spring disposed between the housing and the support. Alternatively, it would naturally be possible to operate the auxiliary accumulators indirectly on the support, for example on an intermediate part of the transmission kinematic chain linking the energy accumulator of the opening mechanism to the support. However, the preferred embodiment offers the advantage of limiting the constraints on this kinematic chain. Advantageously, the housing comprises polar compartments each containing one of said poles, the spring each energy accumulator of the auxiliary mechanism of each pole being disposed in the corresponding polar compartment.

According to one embodiment, the spring is a compression spring disposed inside a cylinder closed by a piston head adapted to come into contact with the support and to transmit to it the force of the compression spring. Alternatively, other types of springs are possible, for example torsion springs or bending.

• la figure 1 représente une vue en coupe d'un disjoncteur selon l'invention, en position fermée non répulsée ;
• la figure 2 représente en coupe le disjoncteur de la figure 1, en position fermée, partiellement répulsée, au passage d'un point mort ;
• la figure 3 représente en coupe le disjoncteur de la figure 1, en position fermée, répulsée ;
• la figure 4 représente en coupe le disjoncteur de la figure 1, dans une position intermédiaire de basculement ;
• la figure 5 représente en coupe le disjoncteur de la figure 1, en position ouverte ;
• la figure 6 représente dans un plan de coupe parallèle à celui de la figure 1, un mécanisme d'accrochage dans une position correspondant à la position fermée répulsée de la figure 3.

Other advantages and features of the invention will emerge from the following description of an embodiment of the invention, given by way of non-limiting example and shown in the accompanying drawings, in which:

• Figure 1 shows a sectional view of a circuit breaker according to the invention, in the non-repulsed closed position;
• Figure 2 shows in section the circuit breaker of Figure 1, in the closed position, partially repulsed, the passage of a dead point;
• 3 shows in section the circuit breaker of Figure 1, in the closed position, repulsed;
• Figure 4 shows in section the circuit breaker of Figure 1, in an intermediate position of tilting;
• Figure 5 shows in section the circuit breaker of Figure 1, in the open position;
• FIG. 6 represents, in a sectional plane parallel to that of FIG. 1, a hooking mechanism in a position corresponding to the repetitive closed position of FIG. 3.

With reference to FIGS. 1 to 5, a high-voltage low-voltage multipolar circuit-breaker 10 comprises a housing 12 divided into an anterior compartment 14 and a rear compartment 16 by an intermediate wall 18. A window 20 made in the intermediate wall allows the communication between the anterior and posterior compartments.

The front compartment 14 serves as a housing for a control device 22, which comprises an energy storage closure mechanism 24 and an opening mechanism 26. This device is known per se and reference is made to the document for details. FR-A-2 589 626. It will suffice to recall here that the opening mechanism 26 comprises a toggle device which comprises two rods 28, 30 hinged to each other by a pivot axis 32, the connecting rod lower 30 transmission member being coupled to a crank 34 of a switching bar 36. An opening spring 38 is anchored between the crank 34 and a fixed retaining cleat 40.

The posterior compartment 16 serves as a housing for the switching bar 36 and for a plurality of poles 42 arranged side by side along a pivot axis 44 of the switching bar 36, in elementary compartments separated by substantially parallel bulkheads. 1 to 5. Each pole 42 comprises a fixed contact member 46 connected to a connection pad 48, a movable contact member 50 connected to a connection pad 52 and an arc extinguishing chamber 54 provided with The movable contact member 50 comprises a movable support 58 pivotally mounted about a geometric axis 60 fixed relative to the housing, and a contact finger 62 pivoting about a geometric axis 64 fixed with respect to the housing, and eccentric with respect to the axis 60. A connecting rod 66 ensures the coupling of the support 58 to the switching bar 36. One end of the finger 62 supports a contact pad 68 destined to ensure contact with a contact pad 70 supported by the fixed contact member 46. The other end of the finger 62 constitutes a cam 72 with two ramps 74, 76 on either side of a top dead center 78. Between the support 58 and the finger 62 is disposed elastic energy store, comprising a spring 82 guided in a cage 84 and pushing out thereof a rod 86 supporting a rotary roller 88. The roller 88 is thus permanently in contact with the cam 72. The elastic energy accumulator forms with the cam 72 a bistable mechanism 80.

Between the housing 12 and the support 58 is disposed an auxiliary elastic energy accumulator 90, visible in its expanded state in FIG. 5, and comprising a compression spring 92 tending to push towards the support 58 a head 94 guided in translation in a cylinder 96 fixed with respect to the housing 12. The front part of the head 94 comprises a bead 98 intended to cooperate radially with the cylinder to provide guidance, and axially with a flange 100 partially closing the cylinder and forming a limit stop .

An attachment device 102, seen in detail in FIG. 6, comprises an arm 104 pivoting about a fixed axis 106 and elastically urged, in the clockwise direction in the figure, by a torsion spring 108. A movable stop 110 is located at the end of the arm 104 and cooperates with a stepped surface 112 of the finger 62. The arm also has a lug 114, adapted to cooperate with a cam 116 located on the support 58.

The intermediate wall 18 supports an end stop 118 of elastomeric material.

The operation of the device is as follows.

In the closed position of FIG. 1, the contact pads 68, 70 are in contact with one another and close the electrical circuit between the connection pads 48, 52. The spring 82 of the bistable mechanism 80 is compressed and the roller 88 cooperates with the ramp 74 so as to ensure a contact pressure between the pellet 68, 70. In the presence of an overcurrent, the electromagnetic forces tend to rotate the finger 62 about its axis in a clockwise direction in the figures, and the bistable mechanism 80 tends to oppose this pivoting. When the intensity of the current exceeds a limitation threshold corresponding to the setting of the spring 82, the finger 62 pivots and passes the dead point 78 of the bistable mechanism 80, shown in Figure 2. Once this dead point has passed, the roller 88 cooperates with the ramp 76 and contributes to push the finger 62 towards the limit stop 118, to the position of Figure 3. The stop 118 acts as a damper and allows, absorbing the surplus energy kinetic, to avoid a rebound of the finger 62. The stop 110 of the attachment device 102 pivots under the bias of its return spring 108 and remains in contact with the stepped surface 112 of the finger 62, so that the mechanism of Hook 102 prohibits the return of the finger 62 in the low position.

To be able to close the circuit breaker, it is necessary beforehand to perform an opening operation by the control mechanism. An opening latch, actuated by an operator or a release, releases the linkage 28, 30, 32. The opening spring 38, assisted by the springs 92 of the auxiliary accumulator 90 of each pole, drives the switching bar 36 rotating in the counterclockwise direction and, by means of the connecting rod 66, pivoting the support 58 about its axis 60 in the clockwise direction from the position of FIG. 3 to the position of FIG. 4 then continues alone to solicit the bar 36 until the position of FIG. 5 is reached.

Between the position of Figure 3 and that of Figure 4, the roller 88 cooperates with the ramp 76 and applies on the finger 62 a force whose moment tends to rotate the finger 62 in the clockwise direction about the axis 64 The damper 118 then acts as an end stop, so that the finger 62 remains stationary; It is therefore the roller 88 which disappears by compressing the spring 82. In this phase, the auxiliary energy accumulator 80 of each pole pushes the support 58 corresponding. The head 94 of the auxiliary accumulator 80 reaches its end position when the support 58 reaches the intermediate tilting position of Figure 4, so that the contact between the head of the auxiliary accumulator and the support ceases.

Beyond this intermediate position of tilting, the roller 88 urges the ramp 74. The movement of the finger 62 in the counterclockwise direction is, however, counteracted by the stop 110 of the catch 102, so that the finger 62 remains relatively immobile, at the close-up game. The action of the opening spring 38 and that of the spring 82 of the bistable mechanism conjugate and drive the support 58 clockwise to its upper position of Figure 5. In an intermediate position between the position of Figure 4 and that of Figure 5, very close to the latter, the cam 116 of the support 58 pushes the lug 114 of the arm 104, so that the latter pivots in the opposite direction of the clockwise and releases the stop 110. However, this release does not cause significant pivoting of the finger 62 in the opposite direction of the clockwise, because the movement of the support 58 is then substantially completed.

From the position of FIG. 6, the closure can be triggered by action on a closing latch which releases a closing spring, pivoting the switching bar from its position in FIG. 6 to its closed position of FIG. 1 The bar 36 drives the support 58 in the counterclockwise direction and the finger 62, only urged by the roller 88 following the movement of the support 58, is also driven. The support 58 compresses and reloads the spring 92 of the auxiliary accumulator 90 at the end of the closing stroke. This incidentally makes it possible to limit the impact at the end of the closing stroke.

As a simplification, the invention has been described considering that each pole comprises a single contact finger 62, a single bistable mechanism 80 and a single auxiliary accumulator 90. In practice, it may be advantageous to provide a plurality of fingers per pole, for example three or five identical fingers pivoting about a common axis 64. Each finger must then be biased by a bistable mechanism, which may be common to several fingers or independent for each finger, so that each finger is biased by a different spring. Support 58 remains unique for each pole. Depending on the size of the support 58, in particular its width in a direction perpendicular to the plane of the figures, it may be advantageous to provide an auxiliary accumulator 90 comprising a plurality of springs arranged in parallel. In practice, three springs arranged in parallel and each acting on a different head, allow to obtain interesting dimensional characteristics.

In practice, it is advantageous to size the auxiliary accumulators so that they release together during their expansion an energy higher than that necessary to compress the spring of the bistable mechanism.

Naturally, the invention is not limited to the embodiment described above. Various modifications are possible within the scope of the invention.

In the previous example, the attachment mechanism 102 performs two functions: it serves on the one hand anti-rebound, in the sense that it avoids, in the event of a very high intensity short circuit generating significant electrodynamic forces that the finger, arrived in the position of Figure 3 and violently striking the damper 118, bounces and returns to close the contact; moreover, it prevents the pivoting of the finger 62 during opening, when the support 58 has just exceeded the intermediate position of tilting. However, depending on the rating of the circuit breaker and the dimensioning of the mechanical parts, it may be envisaged to eliminate this attachment mechanism. The anti-rebound function is then assumed exclusively by the bistable mechanism 80, assisted if necessary by the end-of-stroke damper 118. As for the movement beyond the intermediate tilting position, it can be limited in its magnitude. until it becomes imperceptible, if the speed of the support 58 at the passage of the tilting position is sufficient.

In the embodiment described, the stop 118 provides two functions: it serves on the one hand anti-rebound since it absorbs some of the kinetic energy at the end of travel of the finger 62 to its repulsed position ; it also makes it possible to immobilize the finger 62 when the support 58 pivots from its closed position to its intermediate tilting position. According to an alternative embodiment, these two functions can be provided by different organs. A finger repulsion end stop may for example be arranged on the support 58, and an independent stop disposed on the housing. This arrangement makes it possible to lift together the support 58 and the finger 62 repelled in a first portion of the stroke of the support 58 towards its open position, before the finger 62 encounters the abutment of the housing and does not come to rest with respect to this this.

The invention has been described with reference to a limiting circuit breaker whose fingers pivot about a geometric axis 64 fixed relative to the housing. However, it is also applicable to a limiting circuit breaker as described for example in document GB-A-1 564 412, whose fingers pivot about a fixed axis relative to the pivoting support itself around a fixed axis relative to the housing, and offset from the previous.

The switching bar 36 and the support 58 may constitute a single piece, in which case the rod 66 disappears and the linkage 28, 30, 32 of the control mechanism is directly articulated by one of its ends on the support. This configuration corresponds to the mechanism of GB-A-1,564,412.

The invention is applicable regardless of the type of opening and closing mechanism of the circuit breaker.

Claims (7)

1. A low-voltage limiting circuit breaker (10) comprising

   • a case (12);

   • an opening mechanism (26) comprising at least one energy storage means (38);

   • one or more poles (42) each comprising:

   • a stationary contact part (46) fixed with respect to the case;

   • a stop (118) fixed with respect to the case;

   • a movable contact part (50) comprising:

   • a support (58) movable relatively to the case between a closed position and an open position;

   • at least one movable contact finger (62) movable between a non-repelled position and a repelled position relatively to the support;

   • at least one bistable mechanism (80) comprising a spring (82) arranged between the support and the finger in such a way that it passes via a maximum potential energy when the finger and support are situated relatively to one another in a dead point position, that it tends to return the finger to its repelled position when the finger is situated relatively to the support between its repelled position and the dead point position, and that it tends to urge the finger to its non-repelled position when the finger is situated relatively to the support between its non-repelled position and the dead point position;

   the stop (118) being arranged in such a way that when the finger (62) is positioned in its repelled position and the support (58) moves from its closed position to its open position, the finger (62), once in contact with the stop (118), remains in contact therewith until the support passes beyond an intermediate rocking position relatively to the case, corresponding to the relative dead point position with respect to the finger,

   the opening mechanism (26) being kinematically linked to the support(58) in such a way as to urge the support to its open position when the support is in its closed position;
   characterized in that each pole (42) comprises in addition an auxiliary mechanism comprising one or more energy storage means (90) urging the support (58) to its open position over all or part of the travel of the support between its closed position and the intermediate rocking position, but more so beyond the intermediate rocking position.
2. The circuit breaker according to claim 1, characterized in that the energy storage means (90) of the auxiliary mechanism do not act on the support (58) when the latter is located between its intermediate rocking position and its open position.
3. The circuit breaker according to claim 1, characterized in that the energy storage means (90) of the auxiliary mechanism of each pole (42) are such that when movement of the support (58) of the pole involved takes place, they release an energy greater than or equal to that necessary to move the bistable mechanism(s) (80) of the pole involved to their maximum potential energy.
4. The circuit breaker according to claim 1, characterized in that it comprises in addition latching means (102).
5. The circuit breaker according to claim 1, characterized in that the energy storage means (90) of the auxiliary mechanism each comprise a spring (92) arranged between the case (12) and the support (58).
6. The circuit breaker according to claim 5, characterized in that the case (12) comprises pole compartments each containing one of said poles (42), the spring (92) of each energy storage means (90) of the auxiliary mechanism of each pole being located in the corresponding pole compartment.
7. The circuit breaker according to claim 6, characterized in that the spring (92) of each energy storage means (90) of the auxiliary mechanism is a compression spring arranged inside a cylinder (96) closed by a piston head (94) designed to come into contact with the support (58) and to transmit the force of the compression spring thereto.

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