WO2004038750A2

WO2004038750A2 - Adaptable actuator for switching apparatus

Info

Publication number: WO2004038750A2
Application number: PCT/EP2003/050727
Authority: WO
Inventors: Christian Bataille; Didier Vigouroux
Original assignee: Schneider Electric Industries Sas
Priority date: 2002-10-23
Filing date: 2003-10-16
Publication date: 2004-05-06
Also published as: FR2846469B1; FR2846469A1; AU2003301593A1; WO2004038750A3

Abstract

The invention concerns an adaptable electromagnetic actuator for an electric switch, comprising a mobile coil (15) and a main magnetic circuit (20) consisting of an external yoke (21) and a core (22) made of magnetic material, and of a magnet (25) with radially oriented polarization inserted between the yoke (21) and the core (22). The yoke (21), the core (22) and the magnet (25) form a base (23) of the magnetic circuit (20) which is capable of receiving one or more additional stackable modules (20, 40) consisting each of an additional magnet (35) with radially oriented polarization inserted between an additional core (32) and an external additional yoke (31).

Description

Modular actuator for switching device

The present invention relates to an electromagnetic actuator for electrical switch device, particularly for a relay, a contactor or a contactor / circuit-breaker, which is provided in a modular form so as to easily cover several sizes of actuators from a same basic magnetic circuit and a same coil. The invention also relates to such a switching device.

Electrical appliances switches are used to switch the supply circuit of an electrical load connected downstream of the device. They comprise an electromagnetic actuator, or electromagnet, comprising a movable part which can move under the action in particular of an electric control current flowing in a coil. The power supply circuit includes fixed contacts cooperating with moving contacts carried by the movable part of the actuator. The displacement of the mobile part then opens and closes the supply circuit of the electric charge as a function of control current.

The power supplied by the electromagnetic actuator must obviously be adjusted to the intensity of electric current flowing in the load to be switched so as to be capable of opening and closing the supply circuit quickly and securely to a cost and an optimized footprint. It follows that the same actuator may be efficient only for a given intensity rating. Therefore, it usually takes a large number of different actuators in size and performance, in order to cover a range of switches devices, for example from a few amps to hundreds of amps.

The object of the invention is therefore to standardize and simplify the design of switching devices by proposing an electromagnetic actuator of modular design, that is to say capable of very easily receiving one or more additional modules, enabling it to increase its performance. This significantly reduces the number of different actuators to be designed to cover a whole range of devices, because the same actuator can adapt its performance to different intensity ratings by simply adding additional module (s). The gains obtained in terms of manufacturing cost, design cost, number of parts to be stored, etc. will therefore be significant. For this, the invention describes an electromagnetic actuator comprising a voice coil along a longitudinal axis and a magnetic circuit formed by a main outer yoke and a main core made of magnetic material, and by a main magnet with direction of radial polarization inserted between the yoke main and the main core. The main cylinder head, the main core and the main magnet form a bottom of the magnetic circuit which is capable of receiving one or more additional modules which can be stacked and each composed of an additional magnet with a direction of radial polarization inserted between an additional core and a cylinder head additional exterior.

According to one characteristic, the main magnet and the main yoke are of ring shape and the main core is cylindrical in shape. Similarly, additional magnet and the additional yoke are of ring form and the additional ring is cylindrical in shape.

According to an alternative, the width of an additional module is substantially identical to the width of the main cylinder head. According to another alternative, the width of an additional module is greater than the width of the main yoke, whereby the main yoke can be inserted inside the additional bolt of the additional module.

Other characteristics and advantages will appear in the detailed description which follows with reference to an embodiment given by way of example and represented by the appended drawings in which:

FIG. 1 represents a longitudinal section of an electromagnetic actuator comprising a main magnetic circuit,

FIG. 2 shows this actuator to which two examples of additional modules are added,

- Figure 3 shows the same actuator to which is added two other examples of additional modules.

With reference to FIG. 1, an electrical switching device comprises an electromagnetic actuator comprising a voice coil 15 and a fixed main magnetic circuit 20 composed of a main external yoke 21, a main central core 22 and a main magnet 25 The magnetic circuit is symmetrical along a longitudinal axis X. In the present document, a length represents a dimension along this longitudinal axis X, a width represents a dimension in a radial direction orthogonal to X. The main yoke 21 and the main core 22 are made of magnetic material, such as iron. The main magnet 25 is a permanent magnet with a radial polarization direction, made of a material comprising ferrite or rare earths for higher induction. The magnet 25 is inserted between the yoke 21 and the core 22 on a first portion of length L0 less than the length L1 of the yoke 21 and of the core 22. The other length portion of the yoke 21 and of the core 22 forms a space 24 which constitutes the air gap of the main magnetic circuit 20 and in which the moving coil 15 can move.

In known manner, the coil 15 moves along the longitudinal axis X when it is traversed by an electric current. The strength and direction of movement of the coil is then depending on the direction and intensity of this electric current therethrough. Such an operation corresponds for example to an electromagnetic actuator of the Voice-coil type. The circulation of the permanent magnetic field flowing through the magnetic circuit 20 and generated by the magnet 25 is shown diagrammatically by the arrows 29 of Figure 1. The magnet 25 is designed to be inserted at most just on one side against the central 22 and the other side ring against the outer yoke 21 so as to minimize the gaps between parasites one hand, the magnet 25 and second core 22 and the yoke 21. the main magnet 25 serves also immobilizing together all of the parts of the main magnetic circuit 20.

Preferably, the main magnet 25 and the main yoke 21 are ring-shaped and the primary core 22 is cylindrical along the longitudinal axis X, thus forming circular cross-sections. However, one could also consider other provisions, such as cross sections of substantially square, rectangular or circular arc sections (that is to say with angular sectors) for the main magnet 25, the yoke main 21 and the main core 22. the bottom 23 of the main magnetic circuit 20 is formed by one end of the main yoke 21, the main core 22 and the main magnet 25. Preferably, this bottom 23 has a substantially planar form so as to be able to accommodate an additional module more easily.

In a first embodiment shown in FIG. 2, a first type of additional module 30 with a length L2 is composed of an additional magnet 35 with a direction of radial polarization inserted as closely as possible between an additional central core 32 and an outer yoke additional 31. The width of the additional module 30 is substantially identical to the width D2 of the main circuit 20 which corresponds to the width of the main yoke 21. The width of the additional magnet 35 is substantially identical to the width D1 of the main magnet 25. Likewise, the cross section of the additional module 30 is preferably similar in shape to that of the main circuit 20, that is to say that if the main magnet 25 and the main cylinder head 21 are of toroidal shape and the main core 22 of cylindrical shape, then the additional magnet 35 and the additional cylinder head 31 are also of toric shape, and the additional core 32 of cylindrical shape. The module 30 comprises at least one flat transverse face so as to be able to be pressed against the bottom 23 of the main circuit 20 while minimizing the parasitic air gaps. Preferably, the two transverse faces of the module 30 are planar so that a first face is positioned against the bottom 23 and the other face can receive another additional module 40 superimposed on the module 30.

When such additional module 30 is added to the primary magnetic circuit 20, it increases the performance of the overall magnetic circuit thus obtained to the switching device. Indeed, as the 25,35 magnets have the same direction of radial polarization, the exchange surface, that is to say the passage section of the flow between firstly the magnets 25,35 and the other Apart from the parts made of magnetic material of the magnetic circuit (that is to say: cores 22,32 and yokes 21, 31) extends over a length L0 + L2 instead of a length L0 in the case of single circuit main magnetic 20. thus for the same coil 15 traversed by the same electric current, the magnetic field 29 passing through the gap 24 of the actuator of the overall magnetic circuit will be larger due to the additional module 30, thereby to provide the actuator a greater displacement force.

Thanks to the invention, it is possible to add several additional modules 30, 40 which can be stacked, that is to say stackable on top of each other. Each additional module 40, also consisting of a magnet inserted between a central core and an outer yoke, and has a structure similar widths additional module 30 but may equally well have an identical length L3 or different from the length L2 of the module 30. Figure 2 thus comprises two additional modules 30.40 being superimposed.

In a second embodiment shown in FIG. 3, an additional module 50 of the second type is composed of an additional magnet 55 with a direction of radial polarization inserted as closely as possible between an additional central core 52 and a part of an additional outer cylinder head 51. The cross section of the additional module 50 is preferably similar in shape to that of the main circuit 20, but with certain different dimensions. Indeed, the width D4 of the module additional 50 is greater than the width D2 of the main circuit 20 and the width D3 of the additional magnet 55 is greater than the width D1 of the main magnet 25. Preferably, the width D3 of the additional magnet 55 is substantially equal to the width D2 of the main circuit 20. The module 50 of the second type has the shape of a tube, shown diagrammatically in FIG. 3 by a longitudinal U-shaped section, the branches of which consist of the additional cylinder head 51 of length L5 and of which the central part consists of the additional core 52 and the additional magnet 55 of length L4, much less than the length L5. Preferably, the length L5 is greater than the length L1 of the main cylinder head 21, for example equal to the length L1 + L4, so that the ends of the cylinder heads 21 and 51 are substantially flush. This gives a reinforced width for the overall cylinder head 21, 51.

additional module 50 Dimensions are therefore suitable for the main cylinder 21 can be inserted at the right inside of the additional cylinder 51, to minimize parasitic gaps between these two parts. Furthermore the module 50 comprises a planar central inner surface which is pressed against the bottom 23 of main circuit 20, as shown in Figure 3. Furthermore, the module 50 also comprises a central planar outer face adapted to receive the central inner face of another additional module 60. When such an additional module 50 is added to the main magnetic circuit

20, the performance of the overall magnetic circuit thus obtained for the switch device is increased. In fact, as the magnets 25.55 have the same direction of radial polarization, the cross-section of the flux flow between the magnets 25.55 and the parts made of magnetic material of the magnetic circuit (that is to say: cores 22, 52 and yokes 21, 51) extends over a length L0 + L4 instead of a length L0 in the case of the single main magnetic circuit 20. Thus for the same coil 15 traversed by the same electric current, the magnetic field 29 circulating in the air gap 24 of the overall magnetic circuit of the actuator will be greater thanks to the two magnets 25, 55, which will therefore provide the actuator with a greater displacement force. Compared to the first embodiment, this second embodiment provides an increase in the width of the yoke of the overall magnetic circuit since this width is now equal to the width of the main yoke 21 plus the width of the yoke 51. This arrangement provides the added benefit of reducing the risk of magnetic saturation caused by the increased field magnetic 29 in the magnetic circuit part formed by the outer yokes 21, 51.

The second embodiment also makes it possible to add one or more additional add-on modules 60 the same structure as the additional module 50 of the second type. These additional modules are adapted so that the width of the additional magnet 65 is equal to the D4 width of the yoke 51 which will be inserted into the module 60. Similarly, the length of the yoke 61 is greater than the length L5 of module 50. FIG. 3 thus comprises two additional modules 50, 60 superimposed.

By adding one or more additional modules 30,40,50,60 from a common principal magnetic circuit 20 and base of the same coil 15 is thus obtained very easily a variety of actuators, variable power and modular structure, able to adapt better to the required performance for switches of different calibres devices. To obtain the desired performance, a multitude of different combinations can be envisaged.

For example, it may initially use one or more additional modules of the first type or only use a single additional module of the first type of equivalent length. only one can also use one or more additional modules of the second type. Finally, one can envisage using a combination of both types of additional modules by first placing one or more additional modules of the first type and one or more additional modules of the second type of suitable dimensions.

It is understood that one can, without departing from the scope of the invention, imagine other variants and improvements in detail and even consider the use of equivalent means.

Claims

1. An electromagnetic actuator for electrical switch device, comprising a moving coil (15) along a longitudinal axis (X) and a main magnetic circuit (20) formed by a main outer yoke (21), a main core (22), and by a main magnet (25) to radial polarization direction inserted between the main yoke (21) and the main core (22), characterized in that the main yoke (21), the main core (22) and the main magnet (25) forms a bottom (23) of the magnetic circuit (20) which is capable of receiving an additional module (30) consisting of an additional magnet (35) in radial direction of polarization inserted between an additional core (32) and a additional external cylinder head (31).

2. Electromagnetic actuator according to Claim 1, characterized in that the main magnetic circuit (20) is capable of receiving a plurality of additional modules (30,40,50,60) stacked on top of each other.

3. The electromagnetic actuator according to claim 1 or 2, characterized in that the main magnet (25) and the main yoke (21) are of ring shape and the main core (22) is cylindrical in shape.

4. The electromagnetic actuator according to claim 3, characterized in that the additional magnet (35) and the additional yoke (31) are of ring form and the additional core (32) is cylindrical in shape.

5. Electromagnetic actuator according to one of claims 1 to 4, characterized in that the width of an additional module (30) is substantially identical to the width (D2) of the main cylinder head (21).

6. Electromagnetic actuator according to Claim 5, characterized in that the width of the additional magnet (35) of an additional module (30) is substantially identical to the width (D1) of the main magnet (25).

7. electromagnetic actuator according to one of claims 1 to 4, characterized in that the width (D4) of an additional module (50) is greater than the width (D2) of the main cylinder head (21), so that the main cylinder head (21) can be inserted inside the additional cylinder head (51) of the additional module (50).

8. Electromagnetic actuator according to Claim 7, characterized in that the width (D3) of the additional magnet (55) of an additional module (50) is greater than the width (D1) of the main magnet (25 ).

9. An electromagnetic actuator according to claim 8, characterized in that the width (D3) of the additional magnet (55) of an additional module (50) is substantially identical to the width (D2) of the main yoke (21 ).

10. The electromagnetic actuator according to claim 7, characterized in that the length (L5) of the additional yoke (51) of an additional module (50) is greater than the length (L1) of the main yoke (21).

11. electrical switching apparatus characterized in that it comprises an electromagnetic actuator according to one of the preceding claims.