JPS5857719A - Transformer - Google Patents

Abstract

PURPOSE:To obtain a transformer whereof the assembly is easy, the material cost is low, and further the shield effect is excellent, by winding up a band magnetic shield plate wherein a magnetic material is stuck on one side of an insulator around the outer periphery of a coil, after loading the coil by winding around the magnetic leg of an iron core. CONSTITUTION:An E-shaped laminated iron core 5 and an I-shaped laminated iron core 6 are combined resulting in the constitution of an iron core 4, and a bobbin 7 having coil 10 wherein the primary winding 8 and the secondary winding 9 are wound up is fitted to the central magnetic leg 4a. Thereat, the band insulator 11 constituted of a paper polyester sheet, and acetate sheet, etc. with adhesive 12 on one side is interposed on the outer periphery of the coil 10, and the band magnetic material 13 of an Si steel plate, a magnetic tape, an amorphous magnetic alloy plate, etc. is adhered. Further, the magnetic shield plate 14 is wound around the external surface thereof by using the adhesive 12 resulting in the constitution of an electric closed circuit wherein the insulator 11 is interposed between the magnetic material 13 when putting both ends together. Thus, the shield effect of leak magnetic flux is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transformer having a structure that shields leakage magnetic flux generated from a coil portion.

A conventional transformer of this type was constructed as shown in FIGS. 1 and 2.

That is, a coil 2 consisting of a primary winding and a secondary winding is attached to the central magnetic leg of an El type or EE type iron core 1, and a coil 2 consisting of a primary winding and a secondary winding is attached, and the external faces of this iron core 1 and coil 2 are preformed as shown in Fig. 2. This magnetic shield plate 3 is formed by molding a material with a thickness of about 0.3 to 0.51 al, and eliminates unnecessary Since it also covers the outer surface of the iron core 1, it is large and requires a lot of material, which is disadvantageous in terms of cost, and it is necessary to use spacers to fix the magnetic shield plate 3.

The present invention eliminates the above-mentioned conventional drawbacks, and aims to provide a transformer that is easy to assemble, has low material costs, and has an excellent shielding effect.

In order to achieve the above object, the present invention has a structure in which a magnetic shield plate having a magnetic material pasted on one side of an insulating material is wound around the outer periphery of the coil.

Embodiments of the present invention will be described below with reference to FIGS. 3 to 7 of the drawings.

Reference numeral 4 denotes an iron core constructed by combining an E-shaped laminated iron core 6 and a machined laminated iron core 6, and a coil bobbin 7 has a primary winding ss on the central magnetic leg 4a of this iron core 4.

A coil 10 formed by winding a secondary winding 9 is attached, and on the outer periphery of this coil 10, a silicon steel plate is attached to one side of a band-shaped insulating material 11 such as a paper polyester sheet or an acetate sheet via an adhesive 12. A strip-shaped magnetic material 13 such as a magnetic tape or an amorphous magnetic alloy plate is attached, and a magnetic shield plate 14 provided with 12 layers of adhesive is also wrapped around the outer surface of the magnetic material 13.

The insulating material 11 is used because the magnetic shield plate 14 is located within the iron core 4, so that an electrical closed circuit can be created and maintained. That is, when the magnetic shield plate 14 is wound around the outer periphery of the coil 10 and both ends are overlapped, the insulating material 11 is interposed between the magnetic materials 13 and an electrical closed circuit is formed. There is no configuration.

As shown in FIG. 6, the transformer of the present invention and the conventional transformer are arranged in a search coil 15 of copper wire with an inner diameter of 1001B and a wire diameter of 0.4 m + i1500 tan winding. An alternating current was applied to the search coil 15, and the voltage induced in the search coil 15 was measured.

The results are shown in FIG. 7. In FIG. 7, curve a shows the transformer of the present invention, curve @b shows the conventional transformer, and curve C shows the transformer without a magnetic shield plate. As is clear from this characteristic diagram, it is clear that the present invention has a better shielding effect on leakage magnetic flux from the coil.

Since the transformer of the present invention is constructed as described above, the magnetic shield plate can be simply wrapped around the outer circumference of the coil, making it easy to assemble, and the amount of magnetic material used is small, which is advantageous in terms of cost. As long as the core size is the same, even if the lamination thickness changes, the same product can be used because it is made into a tape, so it has a commonality, and it also has an excellent effect of shielding magnetic flux leakage, so it is of great industrial value. Wow

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional transformer, Fig. 2 is a perspective view of a magnetic shield plate used in the transformer, Fig. 3 is a sectional view showing an embodiment of the transformer of the present invention, and Fig. 4 is the main part of the same. 6 is a sectional view of the magnetic shield plate used in the transformer, FIG. 6 is an explanatory diagram showing the state in which the leakage magnetic flux of the transformer is measured, and FIG. 7 is the present invention, the conventional method, and without the magnetic shield plate. This is a custom-made diagram of the transformer. 4- Core, 7...-Bobbin, 8+...
-Secondary winding, 9... -5ee secondary winding, 10-...
Coil, 11... Insulating material, 12... Adhesive, 13... Magnetic material, 14... Magnetic shield plate. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4 Figure 6

Claims (1)

[Claims] A transformer is constructed by wrapping a coil around the magnetic legs of an iron core, and wrapping a broom-shaped magnetic shielding plate made of insulating material with a magnetic material attached to one side around the outer circumference of the coil.