COMBINED METAL POWDER MAGNETIC CORE AND INDUCTANCE DEVICE FORMED BY SAME

Abstract

A combined metal powder magnetic core and an inductance device formed by same. The combined metal powder magnetic core comprises upper and lower magnet yokes and core columns arranged therebetween; wherein the upper and lower magnet yokes are respectively C-shaped, two ends of the upper and lower magnet yokes are respectively butted with the two core columns to form a magnetic loop, an air gap is arranged at the butted position between the upper and lower magnet yokes, and the interval of the central areas of the air gap is smaller than that of the marginal areas thereof.

Claims

1. A combined metal powder magnetic core, comprising upper and lower magnet yokes and core columns arranged between the upper and lower magnet yokes, the upper and lower magnet yokes each being C-shaped, two ends of upper and lower magnet yokes being respectively butted with the two core columns to form a magnetic loop, and air gaps being arranged at butted positions between the magnet yokes and the core columns, an interval at central area of respective air gap being smaller than an interval at marginal area thereof.

2. The combined metal powder magnetic core according to claim 1, wherein at least one of corner portions at the upper and lower magnet yokes or the core columns is configured as a chamfer.

3. The combined metal powder magnetic core according to claim 2, wherein the chamfer is a rounded corner having a radius greater than the interval at the central area of the air gap.

4. The combined metal powder magnetic core according to claim 2, wherein the chamfer is an oblique angle of 45°, and side length of the oblique angle is greater than the interval at the central area of the air gap.

5. The combined metal powder magnetic core according to claim 1, wherein the upper and lower magnet yokes are an integrally formed magnetic core, and the core columns are formed by splicing a plurality of magnetic blocks.

6. The combined metal powder magnetic core according to claim 1, wherein in a direction perpendicular to a surface of the magnetic core at the central area of the air gap, a tapered magnetic core that gradually decreases in cross section towards the air gap is formed.

7. An inductance device applying the combined metal powder magnetic core according to claim 1, comprising two coil windings and the combined metal powder magnetic core according to claim 1, one of the core columns being inserted into one of the coil windings, and both ends of each of the upper and lower magnet yokes being partially inserted into a central space defined by the coil windings so that the air gaps are surrounded by the coil windings.

8. The inductance device according to claim 7, wherein each core column is combined by two sub-columns arranged in an up-down direction.

9. The inductance device according to claim 7, further comprising an outer holder in which the combined metal powder magnetic core and the coil windings are pressed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1 is a schematic diagram of an inductance device according to the present disclosure.

DETAILED DESCRIPTION

[0017] Hereinafter, the structures of the combined metal powder magnetic core and the inductance device according to the present disclosure will be further described in detail with reference to the accompanying drawings. As shown in FIG. 1, an inductance device 100 includes a combined metal powder magnetic core and coil windings 21, 22. The present disclosure first sets forth a solution by modifying the shape of the magnetic core at the splicing of the magnetic path of the magnetic core; i.e., configuring a combined metal powder magnetic core to comprise upper and lower magnet yokes 11, 12 and core columns 13, 14 arranged between the upper and lower magnet yokes 11, 12. The upper and lower magnet yokes 11, 12 may be respectively C-shaped. The magnet yokes being C-shaped actually defines that both shoulders on both sides of each magnet yoke each have a chamfer R2, and the chamfer R2 may be preferably in a large rounded structure such that each magnet yoke is C-shaped as a whole. Both shoulders of each magnet yoke being chamfered can greatly reduce the magnetic flux leakage at there, thereby not only reducing the magnetic loss, and more importantly, avoiding serious eddy current damage to other surrounding parts containing magnet (such as pieces of iron, copper wires) caused by magnetic flux leakage when running at high power.

[0018] In this connection, two ends of the upper and lower magnet yokes 11, 12 are respectively butted with the two core columns 13, 14 to form a magnetic loop, and air gaps are arranged at the butted positions between the magnet yokes and the core columns. In terms of the air gap 3 at one butted position between the one end of one magnet yoke and one core column, the interval h1 at the central area a of the air gap 3 is much smaller than the interval h2 at the marginal area b thereof, and there is a smooth transition between the central area a and the marginal area b. In this regard, the corner portions of the upper and lower magnet yokes 11, 12 and those of the core columns 13, 14 at the air gaps 3 can all be configured as chamfers. The maximum interval defined by each of the chamfer in the up-down direction constitutes the interval h2 at the marginal area b. Of course, in another embodiment, a chamfer may also be arranged in the orientation of one side to increase the interval h2 at the marginal area b of the air gap 3.

[0019] In this connection, the chamfer may be a rounded corner R1 having a radius greater than the interval h1 at the central area of the air gap 3, preferably greater than 1.5 times h1. In another embodiment (not shown in the FIGURE), the chamfer may be an oblique angle of 45°, and the side length of the oblique angle may be greater than the interval at the central area of the air gap 3, preferably greater than 1.5 times h1. Such structures actually increases the interval at the marginal area of the air gap to allow that the magnetic resistance at the central area of the air gap is much smaller than that at the marginal area, so that the magnetic field moves closer to the central area to reduce the magnetic flux leakage, thereby reducing the eddy current caused by the magnetic flux leakage to the surrounding copper wires. Compared with the traditional solution using a square iron core, under the same working conditions, the magnetic flux leakage penetrated within the cross-sectional area of the coil windings according to the present disclosure is greatly reduced, as such the high-frequency eddy current losses of the coil windings are also greatly reduced.

[0020] The interval at h1 the central area of each air gap 3 may refer to the interval h1 of the central area of each air gap 3 having a millimeter-level (or above but not limit) thickness and h1 may be a magnetic core splicing that is almost close to 0; in this respect, it may also have the effect of reducing the magnetic flux leakage penetrating the coil surface at the splicing.

[0021] In this connection, the chamfered structure is obviously not a manufacturing chamfer that usually exists in traditional chamfering process, nor a commonly referred to as deburring rounding; instead, it may be a chamfer having a rounding angle much larger than the angle of the manufacturing chamfer and that of the deburring rounding. The radius of the manufacturing chamfer or that of the deburring rounding may not be greater than 0.5 mm in product manufacture.

[0022] In a further embodiment, the upper and lower magnet yokes 11, 12 may be an integrally formed magnetic core, and the core columns 13, 14 may be formed by splicing a plurality of magnetic blocks. This can further improve the applicability to high magnetic field intensity.

[0023] The embodiment according to the present disclosure shown in the FIGURE illustrates a rounded magnetic core in a plane direction. In another embodiment, in a direction perpendicular to a surface of the magnetic core at the central area of the air gap, a tapered magnetic core that gradually decreases in cross section towards the air gap 3 is formed. Such tapered magnetic core also has the effect of the present disclosure, and is also one main embodiment of the present disclosure.

[0024] The present disclosure further provides an inductance device 100 applying the combined metal powder magnetic core according to any one of claims 1 to 4. The inductance device may comprise two coil windings 21, 22 and the combined metal powder magnetic core, one of the core columns 13, 14 may be inserted into one of the coil windings 21, 22, and both ends of each of the upper and lower magnet yokes 11, 12 may partially be inserted into a central space defined by the coil windings 21, 22 so that the air gaps 3 may also be surrounded by the coil windings 21, 22. In this connection, the core columns 13, 14 may be in the form of one piece, or they may be combined by two or more sub-columns (not shown in the FIGURE) so as to be adapted to coil windings 21, 22 that have different intervals at the central areas.

[0025] The coil windings according to the present disclosure can be formed by one coil on the left and one coil on the right as shown in FIG. 1. Alternatively, they may be formed by multiple several coils arranged in a unilateral magnetic path as long as the air gaps formed by splicing the magnetic cores are positioned within the central space defined by the coils and have the above-mentioned features, in this connection, such coil windings still have the practical effect of the present disclosure.

[0026] In a further embodiment, an outer holder (not shown in the FIGURE) may also be included, in which the combined metal powder magnetic core and the coil windings 21, 22 are pressed. The outer holder is configured to position the combined metal powder magnetic core and to position the coil windings 21, 22 to prevent them from loosening.