EP0503033A1

EP0503033A1 - Switching device comprising an auxiliary monostable switch coupled to a main switch.

Info

Publication number: EP0503033A1
Application number: EP91917148A
Authority: EP
Inventors: Jean Abot; Christian Lange; Michel Ledroit
Original assignee: Telemecanique Electrique SA
Current assignee: Telemecanique SA
Priority date: 1990-09-27
Filing date: 1991-09-26
Publication date: 1992-09-16
Anticipated expiration: 2011-09-26
Also published as: CA2069617C; MX9101317A; AU652383B2; BR9105909A; RU2070747C1; WO1992006483A1; DE69108893D1; JPH05502753A; FR2667439A1; AU8547991A; DE69108893T2; FR2667439B1; US5323132A; JP2977279B2; EP0503033B1; CA2069617A1

Abstract

Dans ce dispositif, l'interrupteur auxiliaire (13, 14, 15) et l'interrupteur principal (7, 8, 9) sont fermés l'un après l'autre grâce à un mouvement simultané de leurs porte-contacts respectifs et sont ouverts dans un ordre inverse grâce à la présence d'un accouplement libérable (20) qui est débrayé lors de la fermeture et qui est embrayé lors de l'ouverture.In this device, the auxiliary switch (13, 14, 15) and the main switch (7, 8, 9) are closed one after the other thanks to a simultaneous movement of their respective contact carriers and are open in reverse order thanks to the presence of a releasable coupling (20) which is disengaged during closing and which is engaged during opening.

Description

SWITCHING DEVICE COMPRISING AN AUXILIARY SWITCH WITH MONOSTABLE OPERATION COUPLED TO A PRINCIPA SWITCH.

The present invention relates to a switching device comprising at least one main switch able to change state at the end of a transient opening phase or a transient closing phase, under the effect of a member. control, and at least one secondary switch with monostable operation, designed so as to change state, fleetingly during one of the two aforementioned transient phases.

It is generally suitable for all systems involving a switch for which it is desired to detect and, possibly, signal the transient phases of transition to the open state or to the closed state.

It applies particularly well to the production of multi-pole switch devices for the supply of capacitive loads in which the establishment of the load currents is firstly effected through limiting resistors placed in parallel on main switches. still open, using auxiliary switches placed in series with the resistors, these main switches then being closed in turn by a control member having caused the previous closure. """.u"""

These switching devices, which are used in particular in installations where 1On wishes to improve the cos phi, may exhibit malfunctions due to a certain aging of the contact parts.

Respect for the above-mentioned operating sequence is generally obtained by using a control part which is connected to the armature of the electromagnet and simultaneously actuates the moving parts of these switches. Thanks to separate spacings separating the movable contact parts of the two sets of switches and the corresponding fixed contact parts, the same movement first establishes the closing of the auxiliary switches and then that of the main switches which do not undergo as well as the establishment of reduced currents and, then, a constant intensity corresponding to the established regime.

At the moment when, due to the de-excitation of the electromagnet which is operated to decouple the capacitive load, a reverse movement is communicated to the control part, the main switches open first and, as the auxiliary switches are still closed, withstanding an almost negligible cut. The auxiliary switches support most of the shutdown and, being less well sized for this function, alter the life of the device.

Since the fixed and moving parts of these main switches are never set up or open at full load, they cannot benefit from a certain erosion caused by electric arcs, and we are witnessing as a result of a gradual increase in pollution of the contact surfaces which is accompanied by an abnormal increase in the contact resistance and sometimes with the absence of electrical closure of the main poles. The increase in resistance may in turn cause a disturbance in the thermal equilibrium of the switching device, in particular of the auxiliary switch and of the resistors.

For this type of application, the invention aims to provide a switching device operating as described above on closing, but reversing the switching sequence of the contact parts of the main and auxiliary switches during opening. , in order to ensure with certainty the transfer of the current flow from the auxiliary switches to the main switches.

To achieve these results, the invention provides a switching device comprising at least one main interrupter which can pass from an open position to a closed position during a transient closing phase and from a closed position to a open position during a transient opening phase, these two phases being controlled by respective movements of a control member, and at least one auxiliary switch comprising at least one fixed contact and one movable contact connected to said control member through a mechanical connection.

According to the invention, this device is characterized in that said mechanical connection comprises a disengageable coupling designed so as to pass from a coupled position to a uncoupled position, during one of said transient phases and then to return from said position uncoupled to the coupled position, during a subsequent passage of the main switch through the other transient phase.

Advantageously, the aforesaid disengageable coupling is of the stress-breaking type and is designed so as to obtain a disengagement when the control force transmitted to the auxiliary switch by the control member of the main switch, exceeds a predetermined threshold.

According to a first embodiment of the invention, the above disengageable coupling consists of elastic snap-fastening means.

According to a second embodiment intended to overcome a possible wear of surfaces rubbing against each other during frequent coupling and uncoupling, the disengageable coupling uses at least two parts magnetically coupled to one another. other.

Finally, according to a measure finding its advantages in one or the other of these two embodiments, the auxiliary switch and the return spring which is associated with it, are arranged in a housing independent of the body of a contactor device. comprising the main switch, an armature return spring, as well as the electromagnet to which the actuation function of the two types of switches will be assigned.

The invention, as well as alternative embodiments to which it lends itself, will be better understood on reading the description below and on examining the appended figures which accompany it by illustrating:

In FIG. 1, an electrical diagram of a cooked circuit for connecting a capacitive load to a three-phase network, using a device according to

The invention;

In Figure 2, a schematic view of the two switch systems at rest;

In FIG. 3, a first embodiment of a removable mechanical coupling connecting two contact carriers arranged in the extension of one another;

In FIG. 4, a state of the switching apparatus corresponding to a phase of operation where the main switches are closed, while the auxiliary switches are open; and

In Figure 5, a second embodiment of a removable magnetic coupling connecting two contact holders placed opposite.

A circuit 1 for connecting a capacitive load 2 formed by three capacitors - Cl, C2, C3 - to a three-phase network - R, S, T - is shown in Figure 1.

A type of remote-controlled device shown in this figure by way of example to operate this connection uses, on the one hand, an electromagnetic contactor device 3 having in a housing 26 an electromagnet 4, a movable armature 5 , a return spring 5 'which tends to place the latter in a rest position, and an operating member 6 which can advantageously be constituted by an insulating rake or contact carrier on which are movable parts of a set of main three-pole switches 7, 8, 9; on the other hand, a housing 11, which is mechanically associated with the housing 26, comprises a set of auxiliary switches 13, 14, 15 which is actuated by a second operating member 12 which can also be produced in the form of a rake or insulating contact carrier, and being subjected to the action of a clean return spring 12 'whose effects tend to open these switches.

The two operating members, which are advantageously here but not necessarily arranged in alignment, are coupled to one another using a releasable coupling 20 the operation of which will be specified below.

It should be clear that the use of a contactor device here is only to be taken into account in the context of a remote control objective, and that, consequently, manual control means replacing 1 * electromagnet could be used in a device, having the same mechanical and electrical function, possibly grouped together in a single box or box adapted for this purpose; known mechanical means pour¬ rait in this case be arranged between a manual control member and a member for operating the contact holder in order to communicate to the latter sufficiently rapid opening and closing movements.

The auxiliary switches 13, 14, 15 are placed in series with respective limiting resistors - RI, R2, R3 - each of these series assemblies being placed in parallel on a corresponding main switch 9, 8, 7.

Each resistor RI can be split into two series resistors Rla, Rlb placed on either side of the corresponding auxiliary switch 13; the resistances which are here placed outside the third boxes 26, 11 are advantageously connected to the external terminals of the switches using their connection conductors so that good heat dissipation takes place and the manufacturer is not required to modify the conventional boxes available to receive the contactor and the auxiliary contact block, see FIG. 1.

In the state of rest of the device illustrated in this figure, the two sets of main and auxiliary contacts are open thanks to the action of the return springs. As the contact carrier 6 and the contact carrier 12 associated with each other by means of the coupling 20, which is active in the rest position, any movement of the first in direction F will cause at the time of the excitation of the electromagnet a simultaneous displacement of the second.

So that instantaneous load currents, which would take high values during a direct connection of the network and the load, do not circulate in the main supply circuit 21 comprising the main switches, currents of reduced loads are derived in the auxiliary supply circuit 22, at the time of this excitation, by virtue of a prior closure of the auxiliary switches.

This closing, which is carried out a few milliseconds before that of the main switches and which only authorizes the passage of reduced initial currents through the three resistors, is obtained thanks to a difference in the closing distances specific to the contact parts of the main switches - e2 - and auxiliaries - el -, the latter being more reduced.

The desired result is obtained here by a judicious choice of the races of the two contact carriers, that - cl - of the auxiliary rake being made lower than that - c2 - of the main contact carrier by 1 * intervention of a mechanical stop retaining the first while the second continues its course, see Figure 2.

This difference in travel is exploited here so that an automatic disengagement of the coupling 20 and therefore of the two contact carriers occurs, thus making it possible to release the auxiliary contact carrier and allowing it to return to its rest position when the carrier - main contact has already closed the corresponding switches. In order for the complete device to be in a state of rest identical to that which it was before the electromagnet was energized, measures will be taken to return the main contact carrier to the rest position quickly. the clutch of the coupling 20 under the simple effect of its own return spring and reconstitutes the original solidarity of the two contact carriers 6, 12.

A first type of removable coupling 20, visible in FIG. 3 in the coupled state when the complete apparatus is at rest, uses simple mechanical means that can be molded or overmolded during manufacture, or which can at otherwise be the subject of a combination of appropriate spare parts.

An extension 16 of the contact carrier 6 which passes through an opening 27 of the housing 26 of the contactor and is projecting relative to a face (for example a front face or a side face) 30 thereof, has a clearance 28 of which the opposite edges 24, 24 ′ are narrower at the entry than the transverse dimension of a housing 29 which follows it.

The contact carrier 12 of the auxiliary contact box 11 has for its part a fork-shaped extension 19 with elastic branches 17, 18 whose ends 17 ', 18' of the elastic branches 17, 18 are wider than the portion which precedes. The elasticity of this fork, the necessary stiffness of which may require the use of an elastic elastic metal piece 23, allows it to be released from the housing when a sufficient longitudinal traction is exerted between the two carriers. contacts, and allows it to engage therein when a longitudinal thrust is exerted by the contact carrier 6 towards the contact carrier 12. In the state of association of the two housings, which can be obtained by claws 32, 33 present on the opposite faces 30, 31 and in the rest position of two contact carriers 6, 12, the return spring 12 'brought the latter against a clean stop 25' of the housing 11 by developing a relatively low force, and the return spring 5 'of the frame has returned in the same direction the contact carrier 6 in its rest position.

When the contact carrier 6 moves in direction F, following the excitation of the electromagnet, a first stroke - cl - which brings the contact carrier 12 by compressing the spring 12 'is necessary for closing switches 13, 14, 15 and the establishment of an appropriate contact pressure. This movement continues until the contact carrier 12 comes to rest and stop against a first abutment surface 25 of its housing 11, see FIG. 2.

As the stroke - c2 - of the main contact carrier is chosen to be greater than - cl -, the fork 19 emerges from the housing 29 and the branches 24, 24 'thus allowing the return spring 12' to drive in direction G the contact carrier 12 against the stop 25 '; it is clear that the disengagement of the coupling 20 and that the opening of the auxiliary switches which result therefrom only take place when the main switches are themselves being closed and the contact pressure of their moving parts has already reached a sufficient value, see figure 4.

A de-excitation of the electromagnet of the contactor which allows the contact holder 6 to return to its rest position - in direction G - thanks to the return spring 5 'brings the edges of the clearance 28 in contact with the fork 19 by communicating to the latter by percussion a transverse pinch which allows it to penetrate with sliding in the housing 29, so that the clutch of The coupling 20 is again re-established pending a new operating cycle, see FIG. 2.

So that this coupling takes place without longitudinal play, failing which the sequence of successive closings of the switches could be altered, it is advantageous to have in the housing 29 an elastic plate 29 'which gives the fork penetration and a clamp. longitudinal measurement and gives the two contact carriers precise relative positions.

The means which have just been described give their full effectiveness only if the shape of the attraction curve of the electromagnet has been judiciously chosen so that the decelerations caused, on the one hand, by the expenditure of the energy required to disengage the coupling 20 and, on the other hand, by the compression of the spring 12 'are not too great.

Furthermore, the energy developed by the relaxation of the return spring 5 ′ of the armature must be sufficient for the penetration of the fork into the housing to be ensured regardless of the orientation taken by the apparatus in 1 'space.

According to a second embodiment of the removable coupling 40, visible in FIG. 5, the two contact carriers 38, 39 are associated by making use of the adhesion of magnetized 37 and magnetizable parts 36, for example using a ferrite and soft iron.

In order to meet the requirements determined by manufacturing facilities or reductions in technical cost, the magnetizable part and the permanent magnet may be placed on one or the other of the contact carriers.

It is essential to guarantee a regular coupling effort from one maneuver to another. So we can give to at least one of the parts 36, 37 the ability to orient themselves in space, for example by using their retention of elastomeric materials, or by fixing them on molded and articulated portions of or of a contact holder .

Finally, it is clear that the rest positions of the two contact carriers will be close enough to avoid material contact with the permanent magnets, while ensuring sufficient proximity for an automatic magnetic coupling.

The positions of the abutment surfaces which are necessary for the separation of the magnetic and magnetizable parts during the excitation of the electromagnet are here governed by considerations analogous to those which prevail by mechanical coupling.

Other types of detachable coupling can be substituted for unparallel ^'that just described.

Claims

claims

1. Switching device comprising at least one main switch (7, 8, 9) capable of passing from an open position to a closed position during a transient closing phase and from a closed position to an open position during a transient opening phase, these two phases being controlled by respective movements of a control member (6), and at least one auxiliary switch (13, 14, 15) comprising at least one contact fixed and a movable contact connected to said control member (6) via a mechanical connection, characterized in that said mechanical connection comprises a disengageable coupling (20) designed so as to pass from a coupled position to a uncoupled position, during one of said transient phases and then return from said uncoupled position to the coupled position, during a subsequent passage of the main switch (7, 8, 9) through the other transitional phase.

2. Switching device as claimed in claim 1, characterized in that the movable contact of the auxiliary switch (13, 14, 15) is movable between two positions, namely: an open position and a closed position, and in that this movable contact is biased by elastic means (12 ') towards one of said positions.

3. Switching device as claimed in claim 1, characterized in that the aforesaid disengageable coupling (20) is of the stress-breaking type and is designed so as to obtain a disengagement when the control force transmitted to the the auxiliary switch (13, 14, 15) by the control member (6) of the main switch (7, 8, 9) exceeds a predetermined threshold.

4. Device according to claim 3, characterized in that the above disengageable coupling (20) consists of elastic snap-fastening means (24, 24 ', 29; 17, 18).

5. Device according to claim 3, characterized in that the above disengageable coupling (20) comprises two parts (36, 37) magnetically coupled, one of the two parts being connected to the control member (6) of The main switch (7, 8, 9), while the other part is connected to the movable contact of the auxiliary switch (13, 14, 15).

6. Device according to claim 1, characterized in that the two aforementioned switches (7, 8, 9 - 13, 14, 15) are arranged in one and the same housing, the displacements of the aforesaid control member being pro¬ voided manually.

7. Device according to claim 1, characterized in that the main switch and the auxiliary switch are multipolar, and in that, in this case, the above mechanical connection comprising the disengageable coupling connects the moving parts of the two switches.

8. Device according to claim 1, characterized in that the above main switch belongs to a contactor whose electromagnet (4) is coupled to the above control member (6).

9. Device according to claim 7, characterized in that the above contactor is housed in a first housing (26), and in that the auxiliary switch (13, 14, 15) is housed in a second housing (11) capable of be mechanically associated with the first box (26).

10. Device according to claim 1, characterized in that the main switch (7, 8, 9) controls the supply of a capacitive load (2), and the auxiliary switch (13, 14, 15) is placed in parallel on the main switch (7, 8, 9) to supply the load (2) through limiting resistors (RI, R2, R3) in the instant before the main switch closes ( 13, 14, 15), and in that the disengageable coupling (20) is designed so that the disengagement occurs during the closing phase of the main switch (7, 8, 9), l 'auxiliary switch (13; 14, 15) passing into the closed position before the main switch (7, 8, 9) ensuring a pre-supply of the load (2) then then returning to the open position, after declutching , after closing the main switch (7, 8, 9).