JPH06163273A - Electromagnetic power supply device - Google Patents

Abstract

PURPOSE:To obtain an electromagnetic power supply device wherein damage prevention of abutting end surfaces and gap loss reduction are possible. CONSTITUTION:A primary core is made to abut against a secondary core, and a magnetic circuit having a gap is formed. AC power is transmitted from a primary coil to a secondary coil. Magnetic material parts 6, 7 stuck to at least one abutting end surface of both cores absorb or disperse the shock at the time of core abutting, and increase the strength of the core abutting end surfaces. Thereby generation of fracture and crack of the abutting end surfaces of ferrite cores at the time of core abutting are prevented. Since the magnetic material parts 6, 7 have high permeability, gap loss is reduced. Slits formed in the magnetic material parts 6, 7 decrease the eddy current of the magnetic material parts 6, 7.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art An electromagnetic power feeding system in which a primary core wound with a primary coil and a secondary core wound with a secondary coil are butted against each other to form a magnetic circuit with a gap and power is fed from the primary coil to the secondary coil. The shapes of the primary core and the secondary core are U-shaped (Japanese Patent Laid-Open No. 63-151006), E-shaped (see FIG. 4) and coaxial cylindrical (Japanese Patent Laid-Open No. 63-151006).
No. 240403). Since the E-shaped core and the coaxial cylindrical core have a tripod in cross section, they are referred to as tripod cores in this specification.

That is, in the above-described conventional electromagnetic power feeding device using a tripod core, a primary coil is wound around a primary core having an E-shaped section, and a secondary coil is wound around a secondary core having an E-shaped section. Power is supplied by abutting both cores. Also, a U-shaped gapped magnetic circuit can be formed by abutting U-shaped cores instead of the tripod-shaped core, and this case is called a bipod-shaped core.

Usually, a laminated magnetic sheet is used for the core, but ferrite is used in order to increase the frequency to reduce iron loss. Since such a ferrite core is fragile, when the cores are strongly butted, the butted end faces may be chipped or cracked. The mating end faces are covered with a resin layer such as nylon or Teflon.

[0005]

However, the proposal of the above publication is effective in preventing damage to the ferrite core, but the gap is enlarged 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 power conversion efficiency (secondary active power / primary active power).
Adhesion of such a resin layer poses a serious problem in practical use.

Even when the core is made of a laminated magnetic sheet, the flatness of the abutting end faces is poor because the laminating faces are exposed at the abutting end faces. Therefore, when the abutting end faces of both cores are abutted with each other. However, a gap that cannot be ignored is generated between the abutting end faces, and the power conversion efficiency is significantly reduced as in the above case. The present invention has been made in view of the above problems, and an object of the present invention is to provide an electromagnetic power supply device capable of preventing breakage of butt end faces and reducing gap loss.

[0007]

SUMMARY OF THE INVENTION An electromagnetic power supply device of the present invention comprises a primary core and a secondary core which are made of ferrite or laminated magnetic sheets and constitute a gapped magnetic circuit by butting, 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 butting end surface of both cores, The magnetic body part is characterized by having slits for reducing eddy currents.

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

[0009]

FUNCTION AND EFFECTS OF THE INVENTION A gap magnetic circuit is formed by abutting a primary core and a secondary core, and AC power is transmitted from the primary coil to the secondary coil by electromagnetic induction. The magnetic material portion adhered to at least one of the abutting end faces of the cores absorbs or disperses the impact at the abutting of the cores and increases the impact strength of the abutting end faces of the cores. This prevents cracking or chipping of the abutting end faces of the ferrite core due to impact when the cores abut. Further, since this magnetic material portion has a high magnetic permeability, the gap loss is reduced.

Further, the slit formed in the magnetic body part is
The eddy current of the magnetic body part is reduced, and the power conversion efficiency is improved.

[0011]

【Example】

(Embodiment 1) FIG. 1 shows an embodiment of the electromagnetic power feeder of the present invention. This electromagnetic power feeding device includes a power feeding 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 portion is fixed, and the power feeding portion can be displaced manually or automatically.
The butt end surfaces 15 and 35 of No. 3 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 a butted state. The disk-shaped bases 11 and 31 and the axial centers of the bases 11 and 31 are respectively formed. The upright cylindrical central leg portions 12, 32 and the outer peripheral portions of the base portions 11, 31 from the central leg portion 1
Cylindrical end legs 13 and 33 that stand upright in the same direction as 2 and 32
Consists of. The butt end surface 15 is formed by the tip surfaces of the central leg portion 12 and the end leg portion 13, the butt end surface 35 is formed by the tip surface of the central leg portion 32 and the end leg portion 33, and the butt end surfaces 15, 35 are Are matched.

The primary coil 2 is the central leg 12 of the primary core 1.
The secondary coil 4 is wound around the secondary core 3. Further, a thin resin layer 5 is adhered 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 material (for example, silicone rubber or fluoro rubber) can be adopted.

Further, a thin magnetic material portion 6 is adhered to the abutting end surfaces 15 and 35 of the central leg portions 12 and 32 with an adhesive, and the abutting end surfaces 15 and 35 of the end leg portions 13 and 33 are similarly formed.
Also, the thin magnetic body portion 7 is attached by an adhesive.
The magnetic material portions 6 and 7 that characterize 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 as seen from the butt end face 15 side in the axial direction. A spiral slit 61 is formed in the magnetic body portion 6, and strip-shaped slits 71 and 72 are formed in the magnetic body portion 7. The slit 71
Is formed in the centripetal direction from the outer periphery of the ring-shaped magnetic body portion 6,
The slit 72 is formed from the inner circumference of the magnetic body portion 6 in the centrifugal direction. The width of the slits 61, 71, 72 is about 0.5 m
m, the radial pitch of the slits 61 is about 3 m m, 71,7
The length of 2 is about 5 mm, the radial width of the magnetic body part 7 is 7 mm,
The inner diameter of the magnetic body portion 7 was 30 mm and the outer diameter thereof was 35 mm.

Permalloy has a low hysteresis loss and a high saturation magnetic flux density, and has a large tensile strength and compressive strength and a good impact resistance, but it has a drawback of low electric resistance. Is big. The operation of this device will be described below. When both cores 1 and 3 are butted against each other in the state of FIG. 1 and the primary coil 2 is energized, a gapped magnetic circuit is formed between the cores 1 and 3, and an output voltage is induced in the secondary coil 4.

According to this embodiment, since the equivalent length of the eddy current path is extended by the slits 61, 71 and 72 that are cut in a spiral or strip shape, the eddy current loss can be greatly reduced. Have. Further, in this embodiment, since the magnetic material portions 6 and 7 are formed in the spiral shape or the strip shape by the slits 61, 71 and 72, the equivalent length of the eddy current path can be greatly extended, Fragmentation of the magnetic body portion 6 can be avoided, only a small number of magnetic body portions 6 and 7 need to be attached to the abutting end faces 15 and 35, and workability is improved.

Incidentally, such slits 61, 71, 7
For No. 2, it is easy to punch one magnetic foil and form it all at once. Modifications will be described below. Magnetic body part 6,
The material for No. 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 material portions 6 and 7 can be directly formed on the abutting end surfaces 15 and 35 by plating or the like, instead of sticking. However, in the case of a ferrite core, electroless plating is preferable. In this case, to form the slit,
The grease-like substance may be coated on the area where the slit is to be formed before plating, and the grease-like substance may be peeled off after plating.

It is also possible to coat the end leg portion 13 with a spiral magnetic body portion and the center leg portion 12 with a strip magnetic body portion. The magnetic body parts 6 and 7 may be divided into a plurality of parts. However, in the case of adhering such a plurality of magnetic body portions 6 and 7, from the viewpoint of workability, the magnetic body portions 6 and 7 with the slits 61, 71 and 72 are attached to a thin resin film or the like. Butt end face 1 with resin film attached
It can be attached to Nos. 5 and 35, or the resin film can be peeled off thereafter.

FIG. 3 is a sectional view taken along the enlarged arrow in FIG. In the above embodiment, it is of course possible to completely provide the slits 71 and 72 to divide the magnetic body portion 7 into a large number of small pieces. By doing so, the eddy current path can be completely cut off, so that the eddy current loss can be further reduced. (Modification) Instead of the ferrite cores as the cores 1 and 3, a laminated silicon steel sheet, a laminated amorphous sheet or the like can be adopted. In such a laminated magnetic sheet, since the laminated end faces are exposed at the abutting end faces 15 and 35, unevenness is likely to occur. Such unevenness causes an increase in the gap loss, but by providing the magnetic body portions 6 and 7 as in the present embodiment, the unevenness can be filled and the gap loss can be reduced. In addition, in terms of filling the above-mentioned unevenness, the magnetic body portion 6
It is preferable to form by plating or the like.

[Brief description of drawings]

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

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

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

[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)

[Claims] 1. A primary core and a secondary core which are made of ferrite or a laminated magnetic sheet and constitute a gapped magnetic circuit by butting, a primary coil wound around the primary core, and a secondary coil wound around the secondary core. A secondary coil, and a magnetic body part made of a soft magnetic material film having electrical conductivity and attached to at least one butt end surface of the both cores, wherein the magnetic body part has a slit for reducing an eddy current. An electromagnetic power supply device having. 2. The electromagnetic power feeder according to claim 1, wherein the slit divides the magnetic body portion into a spiral shape or a strip shape.