JP3083006B2 - Electromagnetic power supply - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic power supply.

[0002]

2. Description of the Related Art An electromagnetic power supply system in which a primary core wound with a primary coil and a secondary core wound with a secondary coil are joined to form a magnetic circuit having a gap, and power is supplied from the primary coil to the secondary coil. The primary and secondary cores are known as U-shaped (Japanese Patent Application Laid-Open No. 63-151006), E-shaped (see FIG. 4), and coaxial cylindrical type (Japanese Patent Application Laid-Open No.
-240331) is known. Since the cross section of the E-shaped core and the coaxial cylindrical core becomes a tripod, they are referred to as a tripod-type core in this specification.

That is, in the above-described conventional electromagnetic power supply device using a tripod-type core, a primary coil is wound around an E-shaped primary core and a secondary coil is wound around an E-shaped secondary core. Power is supplied by matching both cores. Further, instead of a tripod core, a U-shaped core may be joined to form a square-shaped gap-shaped magnetic circuit, and this case is called a two-leg core.

A laminated magnetic sheet is usually used for the core, but ferrite is used for increasing the frequency to reduce iron loss. Since such ferrite cores are brittle, when the cores are strongly butted against each other, the butted end faces may be chipped or cracked. To prevent this, Japanese Utility Model Laid-Open Publication No. The mating end face is covered with a resin layer such as nylon or Teflon.

[0005]

However, the proposal of the above publication is effective in preventing the breakage of the ferrite core, but the gap is increased by about twice the thickness of the resin layer. In the electromagnetic power supply device, a slight increase in the gap length causes a significant decrease in the power conversion efficiency (secondary active power / primary active power).
The application of such a resin layer has a serious problem in practical use.

[0006] Even when the core is formed of a laminated magnetic sheet, the lamination surface is exposed at the butting end face, so that the flatness of the butting end face is poor. Therefore, when the butting end faces of both cores are butted. As a result, a non-negligible gap is formed between the butted end faces, and the power conversion efficiency is greatly reduced in the same manner as described above. The present invention has been made in view of the above problems, and has as its object to provide an electromagnetic power supply device capable of preventing damage to a butt end face and reducing gap loss.

[0007]

According to the present invention, there is provided an electromagnetic power supply device comprising: a primary core and a secondary core which are made of ferrite or laminated magnetic sheets and form a magnetic circuit having a gap by abutting; and a primary core wound around the primary core. A coil, a secondary coil wound around the secondary core, and a magnetic body portion made of a soft magnetic material film having conductivity and attached to at least one butted end face of the two cores, The magnetic part has a slit for reducing eddy current.

In a preferred embodiment, the magnetic portion is divided into a spiral shape or a strip shape.

[0009]

The primary and secondary cores are joined to form a gap magnetic circuit, and AC power is transmitted from the primary coil to the secondary coil by electromagnetic induction. The magnetic material portion attached to at least one butting end face of both cores absorbs or disperses the shock at the time of butting of the cores, and increases the impact resistance of the butting end face of the core. This prevents cracking or chipping of the butted end face of the ferrite core due to impact at the time of butting of the cores. In addition, since the magnetic portion has high magnetic permeability, gap loss is reduced.

Further, the slit formed in the magnetic body portion is
The power conversion efficiency is improved by reducing the eddy current of the magnetic body.

[0011]

【Example】

(Embodiment 1) An embodiment of the electromagnetic power supply device of the present invention is shown in FIG. The electromagnetic power supply device includes a power supply unit including a primary core 1 and a primary coil 2 and a power receiving unit including a secondary core 3 and a secondary coil 4. In this example, the power receiving unit is fixed, and the power supplying unit is manually or automatically displaceable.
The three butting end surfaces 15 and 35 are detachably butted to form a tripod-type closed magnetic circuit core with a gap.

The primary core 1 and the secondary core 3 are formed in the same shape by using a laminated magnetic sheet or ferrite as a material in abutted state, and are respectively formed along disk-shaped bases 11 and 31 and axial centers of the bases 11 and 31. The upright cylindrical central legs 12, 32 and the central legs 1 from the outer periphery of the bases 11, 31.
Cylindrical end legs 13, 33 standing upright in the same direction as 2, 32
Consists of The butt end face 15 is constituted by the end faces of the central leg 12 and the end leg 13, the butt end face 35 is constituted by the end faces of the central leg 32 and the end leg 33, and both butt end faces 15, 35 are formed. Matched.

The primary coil 2 is a central leg 12 of the primary core 1.
The secondary coil 4 is wound around the secondary core 3. In addition, a thin resin layer 5 is applied to the surfaces of the coils 2 and 4 on the opening side to protect the coils 2 and 4. As the resin layer 5, a resin such as nylon 66 or Teflon or a heat-resistant rubber-based material (for example, silicone rubber or soft rubber) can be employed.

Further, a thin magnetic portion 6 is adhered to the butting end surfaces 15 and 35 of the center leg portions 12 and 32 with an adhesive, and similarly, the butting end surfaces 15 and 35 of the end leg portions 13 and 33 are provided.
Also, a thin magnetic body 7 is adhered by an adhesive.
The magnetic portions 6 and 7 which are features of the present embodiment are made of a conductive permalloy film having a thickness of 10 μm to 2 mm.

FIG. 2 is a front view of the primary core 1 viewed from the butt end face 15 side in the axial direction. A spiral slit 61 is formed in the magnetic part 6, and strip-like slits 71 and 72 are formed in the magnetic part 7. The slit 71
Is formed in the centripetal direction from the outer periphery of the magnetic body portion 6 in the shape of a circular plate,
The slit 72 is formed in the centrifugal direction from the inner periphery of the magnetic body 6. The width of the slits 61, 71, 72 is about 0.5m
m, the radial pitch of the slits 61 is about 3 m m, 71,7
2, the length of the magnetic member 7 is about 7 mm,
The inner diameter of the magnetic body 7 was 30 mm, and the outer diameter was 35 mm.

Permalloy has low hysteresis loss and high saturation magnetic flux density, high tensile strength and compressive strength and good impact resistance, but has the drawback of low electrical resistance, and therefore has the disadvantage of eddy current loss. Is big. Hereinafter, the operation of this device will be described. When the cores 1 and 3 are brought into contact with each other in the state shown in FIG. 1 and the primary coil 2 is energized, a gap magnetic circuit is formed between the cores 1 and 3, and an output voltage is induced in the secondary coil 4.

According to the present embodiment, since the equivalent length of the eddy current path is extended by the slits 61, 71 and 72 cut in a number of spirals or strips, the eddy current loss can be greatly reduced. Have. Further, in this embodiment, since the magnetic portions 6, 7 are formed in a spiral or strip shape by the slits 61, 71, 72, although the equivalent length of the eddy current path can be greatly extended, Magnetic part 6,
7 can be avoided, and a small number of magnetic portions 6,
It is only necessary to attach 7 to the butt end surfaces 15 and 35, and there is an effect that workability is improved.

Incidentally, such slits 61, 71, 7
No. 2 is easy to be formed at once by punching out one magnetic foil. Modifications will be described below. Magnetic part 6,
The material of 7 may be any material having conductivity and high magnetic permeability, and may be pure soft iron, an amorphous magnetic film, or the like.

The magnetic portions 6, 7 can be formed directly on the butted end surfaces 15, 35 by plating or the like, instead of sticking. However, in the case of a ferrite core, electroless plating is preferred. In this case, to form a slit,
A grease-like substance may be coated on a region where a slit is to be formed before plating, and the grease-like substance may be peeled off after plating.

A spiral magnetic body may be attached to the end leg 13 and a strip-shaped magnetic body may be attached to the center leg 12. Each of the magnetic parts 6, 7 can be divided into a plurality. However, in the case where such a plurality of magnetic members 6, 7 are attached, from the viewpoint of workability, the magnetic members 6, 7 with slits 61, 71, 72 are attached to a thin resin film or the like. Butt end face 1 with resin film attached
5, 35, or the resin film can be peeled off thereafter.

FIG. 3 is an enlarged sectional view of FIG. In the above embodiment, it is of course possible to completely provide the slits 71 and 72 to divide the magnetic body 7 into a number of small pieces. In this way, the eddy current path can be completely cut off, so that the eddy current loss can be further reduced. (Modification) As the cores 1 and 3, instead of ferrite cores, laminated silicon steel sheets, laminated amorphous sheets, or the like can be adopted. In such a laminated magnetic sheet, since the laminated end faces are exposed at the butted end faces 15 and 35, irregularities are easily generated. Although such irregularities cause an increase in gap loss, the provision of the magnetic portions 6 and 7 as in this embodiment can fill the irregularities and reduce the gap loss. It should be noted that the magnetic material 6
Is preferably formed by plating or the like.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the electromagnetic power supply device of the present invention;

FIG. 2 is a front view of the magnetic body portion of FIG. 1;

FIG. 3 is an enlarged cross-sectional view of the magnetic body portion of FIG. 1;

[Explanation of symbols]

1 is a primary core, 2 is a primary coil, 3 is a secondary core, 4 is a secondary coil, 6 and 7 are magnetic parts, and 61, 71 and 72 are slits.

Claims (2)

(57) [Claims] 1. A primary core and a secondary core comprising a ferrite or a laminated magnetic sheet and forming a gap magnetic circuit by abutting, a primary coil wound around the primary core, and wound around the secondary core. A secondary coil, and a magnetic part made of a soft magnetic material film having conductivity and attached to at least one end face of the two cores, wherein the magnetic part has a slit for reducing eddy current. An electromagnetic power supply device comprising: 2. The electromagnetic power feeding device according to claim 1, wherein the slit partitions the magnetic body into a spiral shape or a strip shape.