FLEXIBLE ELONGATED INDUCTOR AND ELONGATED AND FLEXIBLE LOW-FREQUENCY ANTENNA

Abstract

The inductor comprises a winding arranged around a core formed by at least two rigid magnetic elements connected in an articulated manner forming an oblong assembly, each comprising: a head end A provided with a circular convex curved surface and a tail end B provided with a circular concave curved configuration, in relation to a transverse axis of the tail, parallel to the transverse axis of the head, and the configuration being complementary to said circular convex curved configuration. The head end A is coupled to the tail end B forming an articulated attachment, and the transverse axes of the head and tail coincide in the coupling area, providing a joint having a variable, adjustable angle, wherein the assembly of said two or more rigid magnetic cores is surrounded by a flexible polymer casing, including magnetic charges that work together to prevent magnetic flux dispersion in the coupling gaps or interstices between the magnetic cores.

Claims

1. A flexible elongated inductor comprising a winding made from a conductive element arranged around a core formed by at least two rigid magnetic cores, made from ferromagnetic material, connected in an articulated manner to one another at their ends, forming an oblong assembly, wherein each of the at least two magnetic cores comprises: a head end A, provided with a circular convex curved surface in relation to a transverse axis of the head: and a tail end B, provided with a circular concave curved configuration in relation to a transverse axis of the tail, parallel to the transverse axis of the head, said circular concave curved configuration being complementary to said circular convex curved configuration, wherein the head end A of one of said magnetic cores is coupled through contact surfaces with the tail end B of an adjacent magnetic core, forming an articulated attachment, wherein said transverse axes of the head and tail of the at least two magnetic cores are coupled to one another coinciding in the coupling area, providing a joint having a variable, adjustable angle, and wherein the oblong assembly of said two or more rigid magnetic cores is surrounded by a flexible polymer casing, including magnetic charges that work together to prevent magnetic flux dispersion in the coupling areas or interstices between said at least two magnetic cores, said flexible polymer casing including microfibers, microparticles and/or nanoparticles of a soft ferromagnetic material present alone or in any combination thereof inside the polymer matrix of said polymer casing, providing said magnetic charges.

2. The flexible elongated inductor according to claim 1, wherein each of he magnetic cores connected in an articulated manner has a rectangular cross section.

3. The flexible elongated inductor according to claim 1, wherein said articulated attachment includes at least one transverse retention configuration formed by a projection and a recess complementary to one another, defined in said head end A and tail end B, respectively, and formed from said ferromagnetic material of the mentioned magnetic cores, preventing said retention configuration from being misaligned in a transverse direction of the magnetic cores coupled to one another.

4. The flexible elongated inductor according to claim 2, wherein said articulated attachment includes at least one transverse retention configuration formed by a projection and a recess complementary to one another, defined in said head end A and tail end B, respectively, and formed from said ferromagnetic material of the mentioned magnetic cores, preventing said retention configuration from being misaligned in a transverse direction of the magnetic cores coupled to one another.

5. The flexible elongated inductor according to claim 1, wherein the flexible elongated inductor has a length greater than 15 cm.

6. The flexible elongated inductor according to claim 5, wherein the flexible elongated inductor has a maximum length of about 60 cm.

7. The flexible elongated inductor according to claim 3, wherein the flexible elongated inductor has a length greater than 15 cm.

8. The flexible elongated inductor according to claim 7, wherein the flexible elongated inductor has a maximum length of about 60 cm.

9. The flexible elongated inductor according to claim 1, wherein said microfibers, microparticles and/or nanoparticles of a soft ferromagnetic material represent about at least 50% of the total weight of the core.

10. The flexible elongated inductor according to claim 4, wherein said magnetic core has a rectangular prismatic configuration, said projection and recess being defined on respective opposing, smaller rectangular faces of both ends A and B of the magnetic core

11. The flexible elongated inductor according to claim 10, wherein said projection and said recess adopt a central position in relation to the assembly of rigid magnetic cores coupled to one another at their ends A and B.

12. The flexible elongated inductor according to claim 10, wherein said projection and said recess adopt a side position in relation to the assembly of rigid magnetic cores coupled to one another at their ends A and B.

13. The flexible elongated inductor according to claim 11, wherein said projection and said recess have a width being 10% of a largest width of the rectangular prismatic body, or have a width being 60% of the largest width of the rectangular prismatic body.

14. The flexible elongated inductor according to claim 1, wherein the inductor has at least 5 magnetic cores coupled to one another and a total extension providing a sag of 2 cm for a length of 30 cm.

15. An elongated flexible antenna formed by a flexible inductor according to claim 1.

16. The elongated flexible antenna according to claim 15, wherein the winding made from a conductive element comprises a conductive wire or a conductive foil.

17. The elongated flexible antenna according to claim 16, wherein said antenna is an LF antenna operating in a range of frequencies of 20 KHz to 300 Khz.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The foregoing and other advantages and features will be better understood based on the following detailed description of an embodiment in reference to the attached drawings which must be interpreted in an illustrative and non-limiting manner, in which:

[0048] FIG. 1a shows a first embodiment of a magnetic core according to the invention and FIG. 2a shows a second embodiment that differ in the arrangement of the retention recess or projection and of the corresponding contact coupling surfaces for linking with other inductors to form a flexible elongated inductor, as described above.

[0049] FIG. 1c shows detailed section view of the coupling between the cores corresponding to the embodiment of FIG. 1a.

[0050] FIGS. 2a and 2b show two embodiments for a magnetic core according to the invention which are equivalent to those illustrated in FIGS. 1a and 1b, although the arrangement of the projection and recess is the other way round.

[0051] FIG. 2c shows the section view of the coupling between two magnetic cores according to FIG. 2b.

[0052] FIGS. 3a and 3b show two other possible embodiments of magnetic cores having the features of the invention. FIG. 3c is a section view of a coupling between the cores having a configuration according to FIG. 3b.

[0053] FIGS. 4a and 4b show another embodiment of magnetic core according to the principles of the invention and FIG. 4c illustrates the element sectioned through the plane of section illustrated in FIG. 4b.

[0054] FIGS. 5a and 5b are yet other embodiments of magnetic cores according to the invention, FIG. 5c illustrating a cross section of the said magnetic core according to the plane of section indicated in FIG. 5b.

[0055] FIGS. 6a and 6b indicate an example of an elongated magnetic inductor formed by the coupling of seven magnetic cores, the assembly being surrounded by a flexible polymer casing, including magnetic charges that work together to prevent magnetic flux dispersion in the coupling areas or interstices (gaps) between said magnetic cores. An elongated flexible antenna will be obtained from the flexible inductor of said FIGS. 6a and 6b, a conductive wire or a conductive sheet suitably coiled around the body thereof.

[0056] FIG. 7 shows a perspective view of a possible embodiment of such LF antenna.

DETAILED DESCRIPTION OF SEVERAL EMBODIMENTS

[0057] As shown in the different embodiments of Figures la to 5c, the invention relates to a flexible elongated inductor formed by a plurality of rigid magnetic cores 10, 11, made from ferromagnetic material, connected in an articulated manner to one another at their ends, forming an oblong assembly, already known in the state of the art, as referred to therein and wherein each of the magnetic cores 10, 11 comprises: [0058] a head end A provided with a circular convex curved surface in relation to a transverse axis of the head; and [0059] a tail end B provided with a circular concave curved configuration, in relation to a transverse axis of the tail, parallel to the transverse axis of the head, and being said circular concave curved configuration complementary to said circular convex curved configuration.

[0060] Said articulated connection or coupling between the magnetic cores is performed such that the head end A of a magnetic core is coupled, through contact surfaces 20a, 20b, to the tail end B of an adjacent magnetic core, forming an articulated attachment around the mentioned transverse axis and the transverse axes of the head and tail of the two magnetic cores coupled to one another 10, 11 coinciding in the coupling area (see, in particular, drawings in section view) providing a joint having a variable, adjustable angle,

[0061] As clearly illustrated in FIGS. 6a and 6b, the invention is characterized in that the assembly of said rigid magnetic cores 11, 12, 13, 14, 15, 16 (six in this embodiment) is surrounded by a flexible polymer casing 50 including magnetic charges that work together to prevent magnetic flux dispersion in the coupling areas or interstices (gaps) between said plurality of magnetic cores 10, 11 coupled to one another.

[0062] As indicated, the mentioned flexible polymer casing includes in a preferred embodiment microfibers, microparticles and/or nanoparticles of a soft ferromagnetic material present alone or in any combination thereof inside the polymer matrix of said polymer casing. Likewise, the mentioned microfibers, microparticles and/or nanoparticles of a soft ferromagnetic material can represent about at least 50% of the total weight of the core. Such casing assures that there are no magnetic flux losses in the joint areas or contact surfaces 20a, 20b of the magnetic cores.

[0063] The mentioned drawings illustrate preferred embodiments wherein each of the magnetic cores 10, 11, 12, 13, 14, 15, 16 coupled to one another or connected in an articulated manner has a rectangular cross section, such that they form a flat, flexible elongated inductor.

[0064] A second relevant feature of the invention lies in the fact that said articulated attachment of the magnetic cores 10, 11 includes at least one transverse retention configuration formed by a projection 30 and a recess 40 complementary to one another, defined in said head end A and tail end B, respectively, and formed from said ferromagnetic material of the mentioned magnetic cores, preventing said retention configuration from being misaligned in a transverse direction of the magnetic cores 10, 11 coupled to one another.

[0065] The features relating to the explained setting-up and arrangement of the coupling between the magnetic cores allow obtaining a flexible elongated inductor with a length greater than 15 cm and preferably greater than 30 cm.

[0066] To use the flexible elongated inductor as an antenna (with a coil around its elongated section), it is considered that a maximum length of about 60 cm is sufficient, although the principles of the invention must not be understood as being limited to said maximum value, considered as sufficient for the desired functionality and performances in the automobile field.

[0067] The proposed magnetic core has a rectangular prismatic configuration, said projection 30 and recess 40 being defined on respective opposing, smaller rectangular faces of both ends A and B of the magnetic core 10, 11, In the different embodiments, the differences lies in where said projection 30 and recess 40 and the corresponding contact surfaces 20a and 20b between the different magnetic cores have been configured.

[0068] Particularly, solutions have been shown wherein the projection 30 and the recess 40, in retention and anti-sliding functions, adopt a central position in relation to the assembly of rigid magnetic cores 10, 11 coupled to one another at their ends A and B, whereas in other examples said projection 30 and said recess 40 adopt a side position in relation to the assembly of rigid magnetic cores 10, 11 coupled to one another at their ends A and B.

[0069] In embodiments suitable for the described functionality, it has been envisaged that said projection 30 and said recess 40 have a span with a width of 10% in relation to the largest width of the rectangular prismatic body, or a width of a 60% in relation to the largest width of the rectangular prismatic body.

[0070] In the embodiment of FIGS. 6a and 6b, the inductor includes seven magnetic cores coupled to one another and a total extension determining that, when held by one end, the free end will bend a maximum of 2 cm for a length of 30 cm.

[0071] As indicated, a flexible LF antenna will be obtained by means of a suitable coil of a conductive metal wire 51 (or alternatively of a conductive foil) arranged around an elongated flexible inductor such as those described.

[0072] FIG. 7 depicts a possible embodiment of an LF antenna using the proposed flexible inductor in which there can be seen the polymer casing 50 and the coil 51 forming the mentioned flexible inductor, boxes made, for example, of a PBT thermoplastic polymer, front part 52 integrating a connector and terminals and rear part 53 and closure gaskets 54, said boxes 52, 53 being attached through a tube 55 likewise made of a PBT plastic, providing a suitable flexibility.