CN116230367A - Ferrite inductance structure - Google Patents

Abstract

The invention relates to the technical field of inductors, in particular to a ferrite inductor structure, wherein a magnetic core is provided with air gaps with different depths, and when a direct current magnetic field is superposed, a part with small air gap depth and a part with large air gap depth are saturated in sequence, so that the direct current superposition characteristic shows soft saturation; meanwhile, the original one-section air gap is divided into a plurality of sections to form a gradient air gap, the outward bulge degree of magnetic force lines at the edge of the air gap is gradually reduced, the degree of magnetic force lines cutting copper wires is gradually reduced, copper loss caused by magnetic force lines cutting a magnetic core is reduced, and the magnetic core loss is reduced.

Description

A ferrite inductor structure

technical field

The invention relates to the technical field of inductance, in particular to a ferrite inductance structure.

Background technique

As we all know, ferrite has high resistivity, high initial permeability, low remanence, low coercive force, low loss and low price. However, due to the low Bs of ferrite, the DC superposition characteristics are poor. Under the same DC superimposed magnetic field strength, the saturation state is reached earlier. This limits the specific application of the material in some occasions. In addition to the influence of Bs on the DC superposition characteristics of the material, the air gap structure also affects the DC superposition characteristics of the material. Therefore, if the DC superposition characteristics of the material are to be further improved, optimizing the air gap structure of ferrite is a more effective way.

Traditional ferrite usually has an air gap parallel to the center column. Although this deep air gap can improve the DC superposition characteristics of the material to a certain extent, it will increase the leakage inductance of the material and weaken other electromagnetic properties such as the inductance of the material. .

Contents of the invention

To achieve the above object, the present invention provides a ferrite inductor structure, comprising:

The magnetic core has at least one first part, the first part is provided with air gaps of different depths, and the degree of swelling of the magnetic force lines at the edge of the air gap is gradually reduced, so that the degree of the magnetic force lines cutting the copper wire can be gradually reduced;

a bobbin covering the magnetic core; and

windings wound on said bobbin outside said first portion.

In some possible implementation manners, the magnetic core is made of one or a combination of materials selected from manganese zinc ferrite, nickel zinc ferrite or magnesium zinc ferrite.

In some possible implementation manners, the magnetic core has a central post and at least one side post, and the air gap is disposed on the central post or the side post.

In some possible implementation manners, the magnetic core includes an upper yoke piece and a lower yoke piece, both of which are provided with the central pillar and the side pillar, and all the upper yoke pieces on the upper yoke piece The center column or side column corresponds to the center column or side column on the lower yoke and forms the air gap at the mating surface.

In some possible implementation manners, the shape of the air gap is a right triangle, and the air gap surface in the air gap is a slope.

In some possible implementation manners, the inclination angle of the air gap surface is 0° to 60°.

In some possible implementation manners, the shape of the air gap is a triangle whose hypotenuse is arc-shaped, and the air-gap surface of the air gap is an arc-shaped surface.

In some possible implementation manners, the winding is composed of a wire and an insulating film covering the wire.

In some possible implementation manners, the wires are copper wires, aluminum wires, silver wires or iron wires.

In some possible implementation manners, the insulating film is formed by coating an insulating varnish containing polyester, polyurethane and polyimide materials on the outside of the wire.

Compared with the prior art, the beneficial effect of the present invention is that: a ferrite inductance structure of the present invention is designed with air gaps of different depths, such design makes the original air gap divided into several sections, forming a gradient air gap. The gap, the degree of outward bulging of the magnetic force lines at the edge of the air gap gradually decreases, which can gradually reduce the degree of magnetic force lines cutting the copper wire, greatly reducing the copper loss caused by the magnetic force lines cutting the magnetic core, and reducing the magnetic core. loss. When a DC magnetic field is superimposed, the part with a small air gap depth and the part with a large air gap depth are saturated in turn, so the DC superposition characteristic shows soft saturation.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained based on these drawings without creative effort.

Fig. 1 is the three-dimensional structure schematic diagram of the ferrite inductance structure that the embodiment of the present invention provides;

Fig. 2 is a partial structural schematic diagram 1 of the ferrite inductor structure provided by the embodiment of the present invention;

Fig. 3 is a partial structural schematic diagram II of the ferrite inductor structure provided by the embodiment of the present invention;

Fig. 4 is a schematic structural diagram of a magnetic core provided by an embodiment of the present invention.

Reference signs:

Magnetic core 10, air gap 11, center column 12, side column 13, upper yoke piece 14, lower yoke piece 15;

skeleton20;

Winding 30.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention. Hereinafter, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

Referring to a ferrite inductor structure shown in FIGS. 1 to 4 , it includes a magnetic core 10, a skeleton 20 and a winding 30, wherein the magnetic core 10 has at least one first part, and the first part is provided with different depths. Air gap 11, the degree of swelling of the magnetic field lines at the edge of the air gap 11 is gradually reduced, which can make the degree of magnetic field lines cutting copper wires gradually reduced; the skeleton 20 is covered outside the magnetic core 10; the winding 30 is wound on the The frame 20 outside the first part. Wherein, in the present application, the shape of the magnetic core 10 may be EE shape, EC shape, EQ shape, ER shape, PQ shape, etc., and is not limited to the above-mentioned cases. In fact, the ferrite inductor structure is designed with air gaps 11 of different depths. This design divides the original air gap 11 into several segments to form a gradient air gap 11. The magnetic field lines at the edge of the air gap 11 bulge outward. The degree is reduced, reducing the copper loss caused by the magnetic force lines cutting the magnetic core 10 , and reducing the loss of the magnetic core 10 . When a DC magnetic field is superimposed, the part with a small depth of the air gap 11 and the part with a large depth of the air gap 11 reach saturation in turn, so the DC superposition characteristic shows soft saturation.

In some possible implementations, the magnetic core 10 favored by the present application is made of one or a combination of materials of manganese zinc ferrite, nickel zinc ferrite or magnesium zinc ferrite, and ferrite The body has high magnetic permeability and low core loss, which is especially beneficial for making large inductors. However, the saturation magnetic flux density of ferrite is low, and it is easy to be magnetically saturated under high current. The saturation of the magnetic core 10 will burn out other components of the switching power supply. For this reason, the design of the application can improve the strength of the material to a certain extent. saturation capacity.

In some possible implementations, referring to Fig. 1 to Fig. 3, since the shape of the magnetic core 10 can be EE-shaped, EC-shaped, EQ-shaped, ER-shaped and PQ-shaped, the present application uses the EE-shaped as an example for detailed description. Note that the magnetic core 10 has a central post 12 and at least one side post 13 , and the air gap 11 is disposed on the central post 12 or the side post 13 . In fact, the design of the air gap 11 is selected according to the requirements. In this application, for the convenience of description, the air gap 11 is selected to be designed on the center pillar 12 in the above description. Actually, the first part in this application can be the central pillar 12 or the side pillar 13 .

In some embodiments, the magnetic core 10 includes an upper yoke piece 14 and a lower yoke piece 15, and the upper yoke piece 14 and the lower yoke piece 15 are provided with the central column 12 and the side column 13, so The central column 12 or side column 13 on the upper yoke piece 14 corresponds to the central column 12 or side column 13 on the lower yoke piece 15 and forms the air gap 11 at the mating surface. In this application, the above-mentioned air gap 11 is designed on the central column 12 as an example. In fact, the cross section of the air gap 11 can be designed in a linear or nonlinear design, as long as it can be multi-step. In fact, in the present application, either the central column 12 or the side column 13 can be provided with an air gap 11 , and the size of the air gap 11 is designed according to the size of the winding 30 .

Referring to Fig. 3, for the convenience of description, in one embodiment of the present application, the shape of the air gap 11 is a right triangle, and the air gap surface in the air gap 11 is a slope. Such a design makes the cross section of the air gap 11 The distribution is linear, so the degree of outward bulging of the magnetic field lines at the edge of the air gap 11 is reduced. In this embodiment, the entire air gap 11 is designed in a linear manner, which is convenient for DC superposition, greatly reduces the copper loss caused by the magnetic force lines cutting the magnetic core, and reduces the magnetic core loss.

In the above improved solution, in order to reduce the degree of outward bulging of the magnetic force lines, the inclination angle of the surface of the air gap 11 is 0-60°.

Referring to FIG. 4 , in an improved embodiment, the shape of the air gap 11 is a triangle whose hypotenuse is arc-shaped, and the air gap surface of the air gap 11 is an arc-shaped surface. Wherein, the arc-shaped design of the air gap 11 actually means that the depth of the air gap increases non-linearly. In fact, the air gap 11 can still be understood as a combination of several air gaps 11 with different depths. In some embodiments, the design of the arc can be an elliptical arc, wherein the ratio of the minor axis to the major axis of the elliptical arc is greater than 1, the minor axis is perpendicular to the mating surface of the magnetic core 10, and the major axis is parallel to the mating surface of the magnetic core 10 .

In some possible implementation manners, the winding 30 is composed of a wire and an insulating film covering the wire. Wherein, the winding 30 is wound on the frame 20, which is designed on the center column 12 in this application; the wires are copper wires, aluminum wires, silver wires or iron wires; and the insulating film is made of polyester, polyurethane An insulating varnish coating of polyimide-based material is formed outside the wire.

The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and any changes or replacements within the technical scope disclosed in the present invention shall be covered within the protection scope of the present invention . Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (10)

1. A ferrite inductor structure, comprising:

the magnetic core (10) is provided with at least one first part, the first part is provided with air gaps (11) with different depths, the degree of swelling of magnetic force lines at the edge of the air gaps (11) is gradually reduced, and the degree of cutting the copper wires by the magnetic force lines can be gradually reduced;

-a skeleton (20) covering the outside of the core (10); and

A winding (30) wound around the armature (20) outside the first portion.

2. A ferrite inductance structure according to claim 1, characterized in that the magnetic core (10) is made of a material of one or a combination of several of manganese-zinc ferrite, nickel-zinc ferrite or magnesium-zinc ferrite.

3. A ferrite inductance structure according to claim 1, characterized in that the core (10) has a center leg (12) and at least one side leg (13), the air gap (11) being provided on the center leg (12) or side leg (13).

4. A ferrite inductance structure according to claim 3, wherein the magnetic core (10) comprises an upper yoke (14) and a lower yoke (15), the upper yoke (14) and the lower yoke (15) are provided with the center pillar (12) and the side pillar (13), and the center pillar (12) or the side pillar (13) on the upper yoke (14) corresponds to the center pillar (12) or the side pillar (13) on the lower yoke (15) and forms the air gap (11) at the mating surface.

5. A ferrite inductor structure according to claim 1 or 3, characterized in that the air gap (11) has a right triangle shape, and the air gap surface in the air gap (11) is a slope.

6. A ferrite inductance structure according to claim 5, characterized in that the angle of inclination of the air gap (11) face is 0-60 °.

7. A ferrite inductance structure according to claim 1 or 3, wherein the air gap (11) has a triangular shape with a sloping side being an arc shape, and the air gap surface of the air gap (11) is an arc surface.

8. A ferrite inductance structure according to claim 1, wherein the winding (30) is constituted by a wire and an insulating film coating the wire.

9. The ferrite inductor structure of claim 8, wherein the conductive wire is copper wire, aluminum wire, silver wire, or iron wire.

10. The ferrite inductance structure according to claim 8, wherein the insulating film is formed by coating an insulating paint containing polyester-based, polyurethane-based and polyimide-based materials outside the wire.

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