EP0650172A1 - Housing for toroidal core and wound toroidal core with such housing - Google Patents

Abstract

This is a housing for a toroidal core of the type formed by two shells (16, 16') which, appropriately juxtaposed and secured to one another, jointly, for winding at least one electrical wire (15), form a central passage (19), and several lateral passages (20) parallel to this central passage (19) and at a distance from it. According to the invention, the shells (16, 16') have complementary nesting means on their junction plane (P), the said nesting means including at least one boss (B1, B2) projecting from this junction plane (P) and a recess (E1, E2) hollowed out on it, and the lateral passages (20) are configured to suit these nesting means. Application, particularly, to differential detection devices. <IMAGE>

Description

The present invention relates generally to toroids used in differential detection devices of the type of those equipping, for example, certain circuit breakers or switches for protecting people.

On such a toroid are wound, on the one hand, at least two primary windings, at the rate of one per line conductor, whether it is a phase conductor or a neutral conductor, and , on the other hand, a secondary winding.

The electrical wires making up these windings must be isolated from the torus they surround, and their turns must themselves be isolated from each other.

To isolate the electrical wires of the torus, it is usual to have it in a box, commonly called a "cover", formed of two shells which, duly faced and secured to one another, jointly form a on the one hand, an annular volume, for housing the toroid, and, on the other hand, a central passage, for winding the electrical wires.

An arrangement of this type is described for example in document FR-A-2 147 816.

Of course, for their connection, the two shells constituting the toroid housing, or "cover", corresponding, have, on their parting plane, complementary fitting means, which, in practice, are reduced overall to a simple rebate .

To jointly isolate the turns of the electrical wires from one another, it is customary, to date, to use insulated and for example sheathed electrical wires.

If, for the secondary winding, the winding does not normally pose any particular problem, in particular because the corresponding electric wire is normally of relatively small diameter, it is not the same for the primary windings.

Indeed, the corresponding electrical wires are then most often of relatively large diameter, and two contradictory requirements are therefore to be observed.

On the one hand, it is a question of passing as close as possible to the box containing the toroid, in order to limit as much as possible the overall overall dimensions of the wound toroid obtained, and, on the other hand, it is a question of avoiding any support too accentuated on this case.

Otherwise, this support could result in a deformation of the housing which, having repercussions on the toroid, would be likely to modify the characteristics of the latter in service.

If, for example, to avoid the consequences of such support, the electrical wires used are flexible electrical wires, it is difficult to pass as close as possible to the housing because, having to be isolated, these flexible electrical wires are inevitably sheathed electrical wires and their sheath is opposed to obtaining sufficiently reduced radii of curvature, to the detriment, therefore, of the bulk.

If, on the other hand, in order to limit this bulk, rigid electrical wires are used, it is difficult to avoid any pressing of these on the housing, with the consequences that this may imply on the characteristics of the toroid.

In fact, with such rigid electrical wires, and independently of the winding difficulties specific to them, relatively high reject rates are quite frequent.

In document FR-A-2 147 816, the two shells constituting the toroidal box form, jointly, for the passage of the electrical wires, parallel to the central passage, at a distance therefrom, and at a distance from each other, side passages.

The central passage is intended for the secondary winding and the lateral passages for the primary windings.

These lateral passages occur in addition to the interlocking means, at the cost of an increase in the overall dimensions of the assembly.

The present invention generally relates to a provision making it possible to avoid this drawback and also leading to other advantages.

More specifically, it firstly relates to a toroid housing of the kind formed by two shells which, duly faced and secured to one another, jointly form, on the one hand, an annular volume, for the housing of a toroid, and on the other hand, for the winding of at least one electric wire, a central passage, and, parallel to this central passage, at a distance therefrom, and at a distance from each other , several lateral passages, this toroid housing being generally characterized in that, the shells having on their joint plane complementary fitting means, these fitting means comprise at least one boss projecting from this plane seal and a hollow recess thereon, and the lateral passages are established by means of these interlocking means; it also relates to any wound toroid using such a toroid housing.

Thus, advantage is taken, according to the invention, of the interlocking means for implanting the lateral passages suitable for establishing the turns of the secondary windings, for the benefit of the diametrical size of the assembly.

In addition, and above all, advantage is taken, according to the invention, of these means of interlocking, to perfect, by the baffle effect that they imply, the insulation of the corresponding wires from the torus .

Preferably, according to the invention, the lateral passages are distributed annularly in two zones, one close to the central passage, the other remote from the latter.

By being duly established from one of these zones to the other, the turns of the primary windings are advantageously systematically separated, and therefore isolated, from each other.

The corresponding electrical wires can therefore be flexible and bare electrical wires, or weakly insulated, their relative insulation as well as that of their turns relative to one another being provided by the insulating material constituting the toroid housing itself.

According to the invention, an additional advantage is therefore taken of this toroid housing.

There is nothing of the sort in document FR-A-2 147 816, in which, on the contrary, the turns of the primary windings must rub shoulders at the outer periphery of the core housing.

According to the invention, the flexible and bare electrical wires, or weakly insulated, thus capable of being used for the constitution of these primary windings can advantageously be wound as close as possible to the toroidal box without any support on that -this is not likely to cause any detrimental deformation.

A minimum overall size can thus be respected, without the risk of a significant scrap rate.

For example, these flexible, bare, or weakly insulated electrical wires are simple braids.

These braids then also participate advantageously continuously in the connection to be established with the members to be serviced, in particular when these are mobile contact members, as is usually the case in differential detection devices.

For their implementation, these braids also advantageously do not require any particular preparation operation, such as stripping or shaping.

They also advantageously do not require significant effort for their winding, which facilitates it.

Because of their fragmented, and therefore ventilated, constitution from multiple strands, these braids also advantageously facilitate the dissipation of heat in service.

Finally, their natural flexibility advantageously makes it possible to connect them at different points to the members to be served, depending on the applications envisaged, for the benefit of standardization of manufacturing.

By their location, the lateral passages of the toroid housing according to the invention also advantageously ensure a balanced distribution of the windings primary around the torus.

The winding of the secondary winding is jointly facilitated, because it is the only one to make use of the central passage of this core box.

As for this toroid housing, it can advantageously be made of a material which, the conditions being equal, has lower mechanical characteristics, and is therefore less expensive, than those usually used to date for the production of a like toroidal box.

In particular, it is possible to use, for the production of this toroidal housing, a relatively ordinary synthetic material and free of any filler such as fibers or the like.

By its natural elasticity, such a synthetic material is finally capable of facilitating the assembly of the two shells constituting this toroid housing.

For example, this assembly can then advantageously be done by snap-fastening if desired.

• la figure 1 est une vue en perspective d'un tore bobiné suivant l'invention ;
• la figure 2 en est, à échelle supérieure, une vue partielle en coupe axiale, suivant sensiblement la ligne II-II de la figure 1 ;
• la figure 3 est, déduite de la figure 1, mais à échelle inférieure, une vue en perspective éclatée du boîtier de tore suivant l'invention et du tore qu'il contient ;
• la figure 4 est, à échelle différente, une vue en perspective de l'une et de l'autre des deux coquilles constitutives de ce boîtier de tore.

The characteristics and advantages of the invention will become apparent from the description which follows, by way of example, with reference to the appended schematic drawings in which:

• Figure 1 is a perspective view of a wound toroid according to the invention;
• Figure 2 is a larger scale, a partial view in axial section, substantially along line II-II of Figure 1;
• Figure 3 is, deduced from Figure 1, but on a smaller scale, an exploded perspective view of the toroid housing according to the invention and the torus it contains;
• Figure 4 is, on a different scale, a perspective view of one and the other of the two constitutive shells of this toroid housing.

As illustrated in these figures, and in a manner known per se, it is, overall, to wind on a toroid 10 disposed within a toroid housing 11, three separate windings, namely, two windings 12A, 12B primary and a secondary winding 13, each consisting respectively of electric wires 14A, 14B and 15.

In the embodiment shown, the windings 12A, 12B and 13 each have several turns.

For example, and as shown, the primary windings 12A, 12B, of which the constituent electrical wires 14A, 14B are of relatively large diameter, comprise a limited number of turns, corresponding in practice to three crossings of the torus 10 in the embodiment shown, while the secondary winding 13, of which the constituent electric wire 15 is of relatively small diameter, has a significantly higher number of turns.

The toroid housing 11 is generally formed of two shells 16, 16 ', which, duly faced and secured to one another, according to methods described in more detail later, jointly form, in a manner known per se, on the one hand, internally, an annular volume 18, for housing the toroid 10, and, on the other hand, externally, along the axis of the annular volume 18, a central passage 19, for the winding of at least one electric wire , in this case, as will appear later, the only electric wire 15.

The two shells 16, 16 ′ also form, for the winding of at least one electric wire, in this case one and / or the other of the electric wires 14A, 14B, at least one lateral passage 20.

In practice, in the embodiment shown, the shells 16, 16 'form, at a distance from each other, several lateral passages 20, for winding one and the other of the electric wires 14A, 14B.

These lateral passages 20 extend generally parallel to the central passage 19, and, according to the invention, they are annularly divided into two zones, namely a zone Z1, close to the central passage 19, and a zone Z2, distant from it. this.

In practice, the numbers of lateral passages 20 per zone Z1, Z2 are different.

In the embodiment shown, they are more numerous in the zone Z1 close to the central passage 19 than in the zone Z2 remote from the latter.

If N is the number of crossings of the toroid 10 desired for the winding of each of the electrical wires 14A, 14B, there are thus, overall, for all of these electrical wires 14A, 14B, 2 N lateral passages 20 in the zone Z1, and 2 N-2 in zone Z2.

In the zone Z1, the lateral passages 20 correspond not only to the turns to be established, but also to the entry and the exit of the electric wires 14A, 14B.

In practice, they are regularly distributed circularly along the same circumference centered on the central passage 19.

In the zone Z2, the lateral passages 20 correspond to the only turns to be established.

As before, they can be regularly distributed circularly along the same circumference of the assembly which, also centered on the central passage 19, is concentric with the previous one.

But, in the embodiment shown, in which the number of crossings N of the torus 10 by the winding of each of the electric wires 14A, 14B is limited to two, and for which, therefore, there are only four lateral passages 20 in the zone Z2, these lateral passages 20 are each respectively established at the top of a rectangle or a square.

In practice, the two shells 16, 16 'are identical to each other.

They comprise, transversely, a joint plane P, with, recessed on this joint plane P, around a central core 22 comprising the central passage 19, an annular recess 23 corresponding half to the annular volume 18 serving as housing for the torus 10.

In the embodiment shown, the shells 16, 16 'have, on their joint plane P, complementary fitting means, namely, at least one boss B1, B2 projecting from this joint plane P for the one of them, and, in correspondence, at least one recess E1, E2 hollow on this joint plane P for the other of these, and, according to the invention, the lateral passages 20 are established by means of these means of interlocking.

As the two shells 16, 16 'are identical, each boss B1, B2 and the recess E1, E2 which corresponds to it have relative implantations on the joint plane P symmetrical with each other with respect to a median plane which, perpendicular to the joint plane P, passes through the axis of the central passage 19.

For the lateral passages 20 of the zone Z1 close to the central passage 19, the same boss B1, elongated circularly, groups together at least two lateral passages 20.

In the embodiment shown, this boss B1 is elongated circularly over approximately a semicircle, and it includes three lateral passages 20.

In a complementary manner, it is the same for the recess E1 which is associated with it.

For the lateral passages 20 of the zone Z2 remote from the central passage 19, the same boss B2 corresponds to only one single lateral passage 20.

In a complementary way, it is the same for the associated E2 recess.

In the embodiment shown, there are therefore, projecting from the joint plane P, two bosses B2, which are arranged in diagonally opposite positions with respect to each other, and, alternately with these bosses B2 , but recessed on the joint plane P, two recesses E2, themselves arranged in diagonally opposite positions relative to each other.

In practice, the bosses B2 have a circular contour, and the same is therefore the case for the recesses E2.

In practice, too, the complementary interlocking means thus intervening between the two shells 16, 16 ′ only extend over a fraction of the height of these, of the order for example of half.

Each recess E1, E2 is therefore limited in depth by a transverse shoulder, or counterbore, 24, and this transverse shoulder, or counterbore, 24 extends substantially at mid-thickness for the shells 16, 16 '.

Because the lateral passages 20 are established by means of the interlocking means that constitute the bosses B1, B2 and the recesses E1, E2, these lateral passages 20 extend in the very thickness of the wall of the shells 16, 16 ', crossing them generally right through their entire height.

The lateral passages 20 of the zone Z1 close to the central passage 19 are established in favor of the central core 22, the thickness of which around the central passage 19 is made sufficient for this purpose.

The side passages 20 of the zone Z2 remote from the central passage 19 are each respectively established by means of local thickenings 25 of the side wall 26 of the shells 16, 16 '.

Anyway, and according to the invention, the lateral passages 20 are, from one to the other of their ends, defined by the same insulating material of the shells 16, 16 '.

Preferably, and as shown, the edge of their outlet to the outside is, at each of their ends, softened by a rounded 28.

In the embodiment shown, the shells 16, 16 ′ also each have projecting fins 29 on their backs, separating fins 29 which radiate in a star from the central passage 19.

In practice, there are thus, on the back of the shells 16, 16 ', eight separation fins 29.

They define two by two as many triangular compartments 30.

Six of these triangular compartments 30 comprise the lateral passages 20, for each of them, a lateral passage 20 of the zone Z1 close to the central passage 19 and a lateral passage 20 of the zone Z2 distant from that -this.

The other two triangular compartments 30 have no lateral passage 20.

In practice, these are two triangular compartments 30 arranged in diametrically opposite positions relative to one another.

In the embodiment shown, the shells 16, 16 ′ also each have protruding from their back, from place to place along their periphery, partition walls 31 whose height is substantially equal to that of the separation fins 29 .

In practice, there are thus four partition walls 31, in the vicinity, each respectively, of the lateral passages 20 of the zone Z2 remote from the central passage 19.

Taking into account, finally, the elasticity that the material constituting the shells 16, 16 'may have, according to the invention, there are provided between these shells 16, 16', for their assembly, snap-fastening means.

In the embodiment shown, these latching means comprise, for each shell 16, 16 ', on the one hand, at least one latching tab 32, which projects in one piece on the plane seal P, at the periphery thereof, and the end of which is shaped as a hook 33, and, on the other hand, in a diametrically opposite position relative to this latching lug 32, a shoulder 34, which, in practice, is directly formed by the back of the shells 16, 16 '.

In the embodiment shown, only one latching tab 32 is provided on each of the shells 16, 16 ', and, in correspondence, the side wall 26 thereof has, externally hollow, a groove 35, which allows embedding the latching tab 32 of the other shell 16, 16 ', and at the end of which the shoulder 34 intervenes, for cooperation with the hook 33 of the latter.

As an indication, and without it being able to result in any limitation of the invention, it can be specified that, for the production of the two shells 16, 16 ′, synthetic materials such as, for example, polyamides, polycarbonates or those of the polyacetal type, can be satisfactory.

During assembly, the two shells 16, 16 'are closed on the torus 10, with a relative interlocking of their bosses B1, B2 and respective recesses E1, E2.

Jointly, they are joined to one another by means of a temporary elastic deformation of their latching lugs 32.

The electric wires 14A, 14B and 15 are then wound on the toroid box 11 thus obtained.

For the electric wires 14A, 14B, only the side passages 20 are used.

In practice, each formed turn extends in isolation in a triangular compartment 30.

The separation fins 29 avoid any contact between the various turns thus formed, and the separation partitions 31 jointly maintain a suitable distance to the electric wires 14A, 14B at their outlet.

According to the invention, the electric wires 14A, 14B can thus be flexible and bare electric wires, or weakly insulated.

Preferably, these are simple braids.

In the side passages 20, the baffle resulting from the interlocking means intervening between the bosses B2 and the recesses E2 advantageously ensures all the desirable path distance between these side passages 20 and the annular volume 18, and, therefore, all the insulation necessary between the electric wires 14A, 14B and the toroid 10.

On the contrary, for the winding of the electric wire 15, the central passage 19 is used.

The turns formed therefore extend in practice in one of the triangular compartments 30 without lateral passage 20.

Usually, the electric wire 15 is therefore a sheathed flexible electric wire.

Of course, the present invention is not limited to the embodiment described and shown, but encompasses any variant.

Claims (16)

Toroidal housing of the kind formed by two shells (16, 16 ') which, duly confronted and secured to one another, jointly form, on the one hand, an annular volume (18), for housing a torus (10), and, on the other hand, for the winding of at least one electric wire, a central passage (19) and, parallel to this central passage (19), at a distance therefrom, and at a distance from each other, several lateral passages (20), characterized in that, the shells (16, 16 ') having on their joint plane (P) complementary fitting means, said fitting means comprise at least one boss (B1, B2) projecting from this joint plane (P) and a recess (E1, E2) hollow thereon, and the lateral passages (20) are established by means of these interlocking means. Toroid housing according to claim 1, characterized in that the lateral passages (20) are distributed annularly in two zones (Z1, Z2), namely a zone (Z1) close to the central passage (19), and a zone (Z2 ) distant from it. Toroid housing according to claim 2, characterized in that the numbers of lateral passages (20) per zone (Z1, Z2) are different. Toroid housing according to any one of Claims 1 to 3, characterized in that the lateral passages (20) extend in the same thickness as the wall of the shells (16, 16 '). Toroid housing according to claim 2, characterized in that, for the lateral passages (20) of the zone (Z1) close to the central passage (19), the same boss (B1), elongated circularly, groups together at least two lateral passages (20). Toroid housing according to claim 2, characterized in that, for the lateral passages (20) of the zone (Z2) distant from the central passage (19), the same boss (B2) corresponds only to a single lateral passage ( 20). Toroid housing according to any one of claims 1 to 6, characterized in that the complementary fitting means intervening between the two shells (16, 16 ') extend only over a fraction of the height thereof . Toroid housing according to any one of Claims 1 to 7, characterized in that the edge of the outlet outside the lateral passages (20) is softened by a rounding (28) at each of their ends. Toroid housing according to any one of Claims 1 to 8, characterized in that the shells (16, 16 ') each have, on their backs, separation fins (29) which radiate in a star from the central passage ( 19). Toroid housing according to any one of Claims 1 to 9, characterized in that the shells (16, 16 ') each project on their back, from place to place along their periphery, partition walls (31 ). Toroid housing according to any one of claims 1 to 10, characterized in that there is provided, between the shells (16, 16 '), latching means (32, 34). Toroid housing according to any one of Claims 1 to 11, characterized in that the two shells (16, 16 ') are identical to each other. Coiled toroid of the kind comprising at least one winding (12A, 12B) of electric wire (14A, 14B) around the toroidal box (11) in which it is housed, characterized in that this toroidal box (11) conforms to any one of claims 1 to 12. Coiled toroid according to claim 13, characterized in that the electric wire (14A, 14B) is a flexible and bare or weakly insulated electric wire. Coiled toroid according to claim 14, characterized in that the electric wire (14A, 14B) is a braid. Coiled toroid according to any one of claims 14,15, characterized in that only the lateral passages (20) formed by the toroid housing (11) are used for the winding (12A, 12B) of the electric wire ( 14A, 14B).

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