The invention relates to a core for a coil, in particular of a switching device, such as an electromagnetic relay.
Cores are designed to carry a coil and are used in switching devices, such as an electromagnetic relay. Usually the coil is wound around a bobbin as a permanent container for the wire to retain its shape and rigidity, as well as to ease the assembly of the windings onto the core. Switching devices are widely used, for example, in home appliances, automation systems, communication devices, remote control devices and automobiles. The function of the switching devices can vary for each application, whereby the applications are often subjected to various size constraints. Consequently, it is a constant desire to provide smaller, particularly slimmer, switching devices. Presently, the width of the switching devices is determined by the core and/or the coil.
A core for a coil of a switching device includes an armature abutment section abutting an armature in a closed condition, an armature bearing section mounting the armature to the core, and a coil section receiving a coil and extending along a longitudinal axis from the armature abutment section to the armature bearing section. The coil section and at least one of the armature abutment section and the armature bearing section extend along separate planes offset from one another perpendicular to the longitudinal axis.
The invention will now be described by way of example with reference to the accompanying Figures, of which:
In the following, a core and an electromagnetic assembly according to the invention are explained in greater detail with reference to the accompanying drawings, in which exemplary embodiments are shown. In the figures, the same reference numerals are used for elements which correspond to one another in terms of their function and/or structure. According to the description of the various aspects and embodiments, elements shown in the drawings can be omitted if the technical effects of those elements are not needed for a particular application, and vice versa, i.e. elements that are not shown or described with reference to the figures, but are otherwise described herein, can be added if the technical effect of those particular elements is advantageous in a specific application.
First, an exemplary embodiment of a core 1 according to the invention is elucidated with reference to
The core 1 for a coil, in particular of a switching device such as an electromagnetic relay, comprises an armature abutment section 2 for abutting an armature in a closed condition, an armature bearing section 4 for mounting the armature to the core 1, and a coil section 6 for receiving the coil. The coil section 6 extends along a longitudinal axis X from the armature abutment section 2 to the armature bearing section 4. In order to provide a core 1 which allows for an assembly of a slimmer switching device, the coil section 6 and at least one of the armature abutment section 2 and the armature bearing section 4, and in an embodiment both, extend along separate planes being offset from one another perpendicular to the longitudinal axis X.
The core 1 may be elongated along the longitudinal axis X, having a longitudinal thin shaped body, meaning that the core 1 may have a length in a direction essentially parallel to the longitudinal axis X, a height in a direction essentially parallel to a vertical axis Y, and a material thickness in a direction essentially parallel to a lateral axis Z, each axis being arranged perpendicular to one another, wherein the length is larger than the height and the height is larger than the material thickness. The separate planes are offset from one another essentially parallel to the lateral axis Z.
Each section may comprise an essentially planar flat face 8, as shown in
In an embodiment, a flat face 10 of the coil section 6 facing the opposite direction to the flat face 8 of the coil section 6 may be laterally offset from at least one of the flat face 10 of the armature abutment section 2 and the flat face 10 of the armature bearing section 4, as shown in
In another embodiment, the flat faces 8, 10 of the coil section 6 may be laterally offset from the respective flat faces 8, 10 of the armature abutment section 2 and/or the armature bearing section 4 in opposite directions, forming a constriction of the core 1 parallel to the lateral axis Z.
Due to the offset, a play 14 in a direction essentially parallel to the lateral axis Z is provided between the flat face 8 of the coil section 6 and the respective flat face 8 of the armature abutment section 2 and/or the armature bearing section 4, as shown in
The coil section 6 may be bent into the separate plane to offset the coil section 6 from at least one of the armature abutment section 2 and the armature bearing section 4. For providing an easy and cost-efficient way of forming the offset between the coil section 6 and at least one of the armature abutment section 2 and the armature bearing section 4, the coil section 6 may be formed as an embossment 16 of the core 1.
The armature abutment section 2 and the armature bearing section 4 may be aligned in a direction essentially parallel to the longitudinal axis X, meaning that the middle axis parallel to the longitudinal axis X of the armature abutment section 2 is aligned with the middle axis, parallel to the longitudinal axis X of the armature bearing section 4. The flat face 8 of the armature bearing section 4 and the armature abutment section 2 may be aligned with one another along the longitudinal axis X. In another embodiment, the armature abutment section 2 and the armature bearing section 4 may also be laterally offset from one another.
The armature abutment section 2, the armature bearing section 4, and the coil section 6 may be formed integrally with one another as a monolithic core 18. The core 1 may be a magnetic core, such as an iron core. In an embodiment, the core 1 may be formed of a soft magnetic material, i.e. a magnetizable material having a low coercivity such as hysteresis, silicon steel or ferrite. The core 1 or at least the coil section 6 may comprise a soft iron, since it does not retain its magnetism when the current is switched off; or in other words, it does not become permanently magnetized.
The armature abutment section 2 and the armature bearing section 4 may each form an end of the core 1, the ends being arranged opposite to one another along the longitudinal axis X, as shown in
At least the armature bearing section 4 may comprise a material thickness 26 that is less than the material thickness 24 of the coil section 6. Consequently, an armature having a larger material thickness may be employed without increasing the total width dimension of the switching device.
The material thickness 26 of the armature bearing section 4 and a material thickness 28 of the armature abutment section 2 may be the same. However, it may be desirable to have a more rigid armature abutment section 2, so that it does not get deflected by the force of the armature pushing against the armature abutment section 2. Therefore, the material thickness 28 of the armature abutment section 2 may be larger than the material thickness 26 of the armature bearing section 4.
However, in order to keep the core 1 simple and easy to manufacture, in another embodiment the material thickness 24 of the coil section 6, the material thickness 26 of the armature bearing section 4 and the material thickness 28 of the armature abutment section 2 may be essentially the same.
As can be seen in
The wings 32 of the armature abutment section 2 and the armature bearing section may extend parallel to one another, whereby the wings 32 of the armature abutment section 2 may extend further than the wings 32 of the armature bearing section 4. Therefore, a larger surface may be provided by the armature abutment section 2 for the armature, so that the force at which the armature abuts the armature abutment section 2 can be evenly distributed over a larger area. Furthermore, the magnetic flux at the armature abutment section 2 may be increased, allowing to overcome the air gap between the armature abutment section 2 and the armature in the open configuration.
The armature abutment section 2 and the armature bearing section 4 may comprise wings 32 extending beyond the coil section 6 at either side along the vertical axis Y. Therefore, the core 1 comprises an essentially H-shape, as shown in the embodiment of
At a transition area 34 between the coil section 6 and at least one of the armature abutment section 2 and the armature bearing section 4, shown in
The coil 40 may be directly wound onto the coil section 6, further reducing the size of the magnetic assembly 38, as no additional bobbin must be provided. However, a bobbin may also be formed by overmolding the coil section 6. The bobbin may be formed of a resin material and be adapted to securely hold the coil 40 in position.
To further separate the coil section 6 from at least the armature bearing section 4, a flange 42 may be provided at the transition area 34 between the coil section 6 and the armature bearing section 4. The flange 42 may secure the coil 40 at the coil section 6 and prevent the coil 40 from moving in a direction parallel to the longitudinal axis X. The flange 42 may be formed by overmolding and may comprise a resin material. The flange 42 may ensure that the mounted coil 40 retains its shape in the coil section 6.
To further facilitate the molding of the flange 42, the flange 42 may be formed integrally with a mounting bracket 44 as a monolithic part 46. Consequently, the flange 42 is a part of a larger component, which is easier to mold. The mounting bracket 44 is overmolded to the armature bearing section 4, and may be adapted to secure the armature in at least a direction essentially parallel to the longitudinal axis X.
In this embodiment shown in
Since the coil section 6 comprises an elongated thin cuboid shape, the coil 40 wound onto the coil section 6 comprises a rectangular or oval shape in a cross section in a plane essentially perpendicular to the longitudinal axis X. Therefore, the width of the coil 40 is further reduced, allowing for an even slimmer assembly of the switching device.
The opening 52 may be aligned with the coil section 6, so that the coil section 6 may at least partially be received in the opening 52. Therefore, the width of the coil section 6 and the coil 40 at the side facing the armature does not negatively affect the width of the magnetic assembly, allowing the assembly of an even slimmer switching device.
The distal end of the frame 50, being distanced from the armature bearing section 4, may be aligned with the armature abutment section 2 so that the distal end of the frame 50 may abut the armature abutment section 2 at a closed position of the armature 48. The armature 48 may be adapted to directly contact a contact spring of the switching device, or may be provided with an actuating arm 58 molded to the distal end of the frame 50.
A cut view of an exemplary embodiment of a switching device 60 is shown in
The armature 48 may be moved from an open position, wherein the armature 48 is pivoted away from the armature abutment section 2 as shown in
The actuating arm transfers the movement to a contact spring 62, either closing or opening the contact between the contact spring 62 and a complementary contact spring 64.
As can be seen in
A switching device, such as an electromagnetic relay, may comprise a magnetic assembly 38 according to any of the above-mentioned configurations.
Number | Date | Country | Kind |
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19215178.5 | Dec 2019 | EP | regional |
This application is a continuation of PCT International Application No. PCT/EP2020/085152, filed on Dec. 9, 2020, which claims priority under 35 U.S.C. § 119 to European Patent Application No. 19215178.5, filed on Dec. 11, 2019.
Number | Date | Country | |
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Parent | PCT/EP2020/085152 | Dec 2020 | US |
Child | 17836318 | US |