JPS59144112A - Core assembly for leakage transformer - Google Patents

Abstract

PURPOSE:To prevent the displacement of a ring core by forming both sides of center leg part of a pair of E type ferrite cores as the flat surface and by forming a partially flat surface which is suited to the external circumference of center leg at the internal circumference of the ring core to which the center leg is inserted. CONSTITUTION:External leg plates 3, 4 are coupled with both sides of rear pillar wall plate 2 at the E type ferrite core 1. The center leg 5 is formed at the flat surfaces 5a, 5b where both sides opposing each other to the legs 3, 4 are parallel to the plate surface of legs 3, 4. Moreover, the ring core 6 is provided with a through hole 7 having a pair of flat surfaces 7a, 7b corresponding to the leg 5. The ferrite cores 1, 1 are combined like a squarish 8-shape and the ring core is loaded between the center legs 5, 5'. As a result, the ring core 6 does not rotate for the center leg 5 and displacement of it can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a core assembly for a leaky transformer used in a ballast for a discharge lamp or the like.

Conventionally, a primary coil and a secondary coil are wound around a bobbin or core so that the coil axes coincide, and a plate-shaped or rod-shaped core called a niva core or shunt core is placed between the primary coil and the secondary coil. A leaky transformer is known. However, the conventional core for this type of transformer is of a type in which silicon steel plates are laminated, which is cumbersome to manufacture, has a relatively large overall shape, and has a large core loss. Particularly when used at high frequencies, the influence of iron loss is large, resulting in a reduction in efficiency.

In order to solve this problem, a transformer core assembly as shown in FIG. 1, which is entirely composed of a ferrite core, has been proposed.

To briefly explain this # configuration, E type ferrite core l
The square outer legs 3 and 4 are connected to both ends of the rectangular back column wall 2, and in the center of the back column wall 2, the outer legs 3.4 and #1 form a cylindrical center N5 of the same length. ing. The hollow 7-elite core or ring core 6 is a cylindrical core with a through hole 7 in the center. 2 E-type ferrite cores 1゜1
' are combined in a Japanese-shape as a whole with their legs 3 and 3', 4 and 4', and 5 and 5' facing each other, and a ring core 6 is inserted near the tips of the central legs 5 and 5'. As shown in FIG. 2, a primary coil 8 and a secondary coil 9 are wound around each central leg 5° 5', thereby forming a leakage transformer.

By molding an E-type ferrite core 1 as shown in Figure 1)
To manufacture, as shown in FIG.
11", pressurize in the vertical direction to mold each part. In this case, since the central leg 5 has a completely circular cross section, when molding is completed, the tips of the upper and lower chambers 10' and 11' of the central leg part 10a and lla interfere with each other, causing a risk of damaging the mold and causing a dimensional error in the cylindrical central leg 5.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a core assembly for a leaky transformer which eliminates the above-mentioned disadvantages and which is capable of holding a ring core attached to a central leg in a predetermined position.

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

FIG. 4 is a side view of the E-type 7 ferrite core 1 according to the present invention as seen from the leg side, and FIG. 5 is an end view of the ring core 6 attached to the center leg 5 of the E-type ferrite core 1. The plate-shaped outer legs 3 and 4 are connected to both ends of the plate-shaped back column wall 2, which is the same as the conventional example explained in FIG. 1, but in the embodiment shown in FIG. This is a cross section of a small coin. That is, both side portions facing the outer legs 3 and 4 are formed into flat surfaces 5a+5b parallel to the plate surfaces of the outer legs.

Further, the ring core 6 is also formed with a through hole 7 having a pair of flat surfaces 7a and 7b corresponding to the central leg 5, as shown in FIG. FIG. 6 shows a core assembly in which E-type ferrite cores 1 and 1' as shown in FIG. 4 are combined in a Japanese letter shape, and a ring core 6 as shown in FIG. It is a side view of. The flat surface 5ai or 5b of the central leg 5 or 5' and the flat surface 7a of the hole 7 of the phosphor core 6
Due to the contact with the +7b portion, the ring core 6 does not rotate relative to the center leg, thereby preventing the ring core 6 from being misaligned.

FIG. 7 is a sectional view showing a mold for molding the E-type 7-eight core 1 according to the present invention. In this case center leg 5
has a flat surface 5aj5b, so the tip 1 of the upper and lower molds
0b and Ilb do not interfere with each other, improving the shape and dimensional accuracy of the molded product.

[Brief explanation of the drawing]

Fig. 1 is a trunk view of a conventional transformer core assembly, Fig. 2 is a plan view of a leaky transformer using the core assembly of Fig. 1, and Fig. 3 is a top view of a leaky transformer using the core assembly of Fig. 1.
The figure is a schematic view showing the molded state of the core assembly in Figure 1, Figure 4 is a side view of the E-type ferrite core according to the embodiment of the present invention, seen from the leg side, and Figure 5 is a diagram showing the embodiment of the present invention. FIG. 6 is an end view of a ring core applied to the example, FIG. 6 is a 1,000-meter view of a transformer core assembly according to the present invention, and FIG. 7 is a mold for an E-type ferrite core according to the present invention, in its operating state. FIG. 1.1'... E-type ferrite core, 3.4... Outer leg, 5... Center leg, 6... Ring core, 5 a + 5 bs 7 a #7 b ''' flat surface, 7 -・Negative through hole, 10. 10', 1 (1'
-...Top mold, 11.11', 11"...Bottom mold. Agent Patent Attorney Rikichi Kawa Figure 1 1° Figure 2 Figure 3 Figure 4 Figure 5 Figure 7 Page 1 Continued 0 Author: Yoshinobu Onodera Inside Toshiba Electric Materials Corporation's Horikawa-cho Plant, 72 Horiyo-cho, Saiwai-ku, Kawasaki City0 Author: Aochi Minamijo Inside Toshiba Electric Materials Corporation's Horikawa-cho Plant, 72 Horiyo-cho, Saiwai-ku, Kawasaki City■ Applicant Toshiba Electric Materials Corporation 1-1-43 Shibaura, Minato-ku, Tokyo

Claims (1)

[Claims] It has a pair of ferrite cores in which two outer legs and a roughly cylindrical central leg are connected by a dorsal wall, and a ring core into which the central legs are inserted, and the pair of ferrite cores are arranged so that the legs face each other. In the core assembly for a leaky transformer, the ring core is arranged in a Japanese character shape, and the ring core is attached almost near the tip of the center leg, wherein both sides of the center leg are formed into flat surfaces, and the ring core has a ring core attached to the inner circumference of the ring core. A core assembly for a leaky transformer characterized by forming a partial flat surface to match the outer peripheral shape of the central leg.