JPH0817648A - Transformer - Google Patents

Abstract

PURPOSE:To provide the title transformer formed of a bobbin wound up with a coil around the central leg part of a pair of E type ferrite cores to be engaged with the transformer for avoiding the cracking due to the heat contraction of the cores. CONSTITUTION:The title transformer is formed of a pair of E type ferrite cores 1 and a bobbin 3 wound up with a coil to be engaged with the central leg part of these cores 1. At this time, the upper side core out of the pair of cores and one junction surface of the bobbin are coated with bonding agents 8 and 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer using two E-type ferrite cores.

[0002]

2. Description of the Related Art Generally, for example, in a deflection circuit or a switching power supply circuit of a television receiver, a transformer or a choke to which a ferrite core is applied is used. As such a transformer, one in which two E-type ferrite cores are combined and a gap is provided between magnetic legs is usually used.

FIG. 3 is an external perspective view of an example of a conventional transformer [hereinafter referred to as "conventional example"], and FIG. 4 is a plan sectional view thereof. Reference numeral 1 denotes an E-type ferrite core, in which two E-type ferrite cores 1 are combined, and a coil 4 wound around a bobbin 3 is fitted in the center leg thereof. In such a transformer, after fixing the two E-type ferrite cores 1 with the polyester tape 6 in order to fix the E-type ferrite core 1 and the bobbin 3 and to prevent the roaring noise due to the magnetostrictive vibration of the E-type ferrite core 1, Is impregnated with resin 5.

[0004]

However, in such a structure as seen in the conventional example, since the whole is impregnated with the resin, the E-type ferrite core and the bobbin are completely adhered, and the E-type ferrite core and the bobbin are The space will be filled with resin. Therefore, when the temperature of the transformer decreases and the bobbin contracts or the temperature of the transformer increases and the bobbin expands, the E-type ferrite core cracks due to the difference in the thermal contraction rate due to the difference in material between the E-type ferrite core and the bobbin. And the E-type ferrite core cracked.

An object of the present invention is to provide a transformer for fixing the E-type ferrite core and the bobbin without causing a crack in the E-type ferrite core by eliminating the above-mentioned drawbacks of the conventional example.

[0006]

To achieve this object, the present invention relates to a bobbin fitted to a central magnetic leg of a pair of E-type ferrite cores and a pair of E-type ferrite cores from above. An adhesive is applied to one of the joining surfaces of the E-type ferrite core to be joined to the bobbin, which is inserted into the bobbin, to join the bobbin and the E-type ferrite core.

That is, according to the present invention, a bobbin is provided in which two magnetic legs of two E-type ferrite cores are combined with a magnetic pole facing each other with a gap provided therebetween, and the coil legs are fitted to the central leg of the E-type ferrite core and wound. Of the two E-type ferrite cores and the lower contact surface of the horizontal leg of the E-type ferrite core that is fitted to and contacts the upper contact surface of the bobbin.
This is a transformer in which an E-type ferrite core and a bobbin are bonded to each other by applying an adhesive on one of the contact surfaces.

[0008]

According to the present invention, the E-type ferrite core and the bobbin are joined at only one point, and the E-type ferrite core and the bobbin are joined together.
Even if the E-type ferrite core and the bobbin contract, tension is not applied to the E-type ferrite core, and thus the generation of cracks in the E-type ferrite core can be prevented.

[0009]

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

FIG. 1 is a plan sectional view of a transformer according to an embodiment of the present invention, and FIG. 2 is an external perspective view thereof. In FIG. 1, 1 is a pair of E-type ferrite cores, 2 is a center leg thereof, 3 is a bobbin around which a coil is wound, and a pair of E-type ferrite cores 1 and bobbin 3 are fitted with a conventional example. Is the same.
8 is an adhesive, which is the upper part of the bobbin 3 and the E-type ferrite core 1.
It is applied only to one side of the upper two of the joining surfaces with the E-type ferrite core 1. The reason why the coating is applied to only one side is that the crack 7 in the E-type ferrite core 1 due to the thermal expansion and contraction of the bobbin 3 and the E-type ferrite core 1 due to the difference in thermal expansion coefficient between the two is avoided. The means of joining the two while providing an escape area. The pair of E-type ferrite cores 1 are fixed by a polyester tape 6, and the pair of E-type ferrite cores 1 may be coated with an adhesive 9 if necessary.
Increase the joint strength between each other.

[0011]

As is apparent from the above description, according to the present invention, the E-type ferrite core and the bobbin are bonded at one place with an adhesive. Between them does not exert force on each other, and because the whole is not filled with resin, it is possible to prevent the tension due to the contraction of the bobbin from acting on the E-type ferrite core and prevent the E-type ferrite core from cracking. It is possible to exert a special effect.

[Brief description of drawings]

FIG. 1 is a plan sectional view of a transformer according to an embodiment of the present invention.

FIG. 2 is an external perspective view of a transformer according to an embodiment of the present invention.

FIG. 3 is an external perspective view of a conventional transformer.

FIG. 4 is a plan sectional view of a conventional transformer.

[Explanation of symbols]

 1 E-type ferrite core 2 Central magnetic leg 3 Bobbin 4 Coil 5 Resin 6 Polyester tape 7 Crack 8 Adhesive 9 Adhesive

Claims (1)

[Claims] 1. A bobbin in which two E-type ferrite cores are combined with a magnetic pole facing each other with a gap provided therebetween and which is fitted to the central leg of the E-type ferrite core and wound with a coil. Of the two E-type ferrite cores, one of the two contact surfaces with the lower contact surface of the horizontal leg of the E-type ferrite core fitted into the upper contact surface of the bobbin and in contact with the upper contact surface. Apply adhesive to one of the contact surfaces,
A transformer comprising the E-type ferrite core and the bobbin joined together.