JPH0566945U - Trance - Google Patents

Abstract

(57) [Abstract] [Purpose] The purpose is to reduce the noise that occurs with performance improvement and higher frequencies in transformers used for switching power supplies and the like. [Construction] A conductor wire is wound around the winding frame portion 1 of the coil bobbin 4,
A bottom plate 1 in which a protective case 11 made of plastic or the like and a magnetic material 10 are integrally molded in a transformer body incorporating a magnetic core 9
An inductance component is formed in the pin terminal 5 by covering with 3 and a bottom-back type noise reduction transformer is realized, and noise generated from the switching power supply is absorbed and attenuated by the magnetic material 10 to reduce the noise.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a transformer used in various power supply equipment, video equipment, audio equipment, industrial equipment, telephone-related equipment and the like.

[0002]

[Prior Art]

 5A and 5B show the internal structure of a conventional transformer. As shown in the figure, the coil bobbin 22 having the flanges 20 at both ends, and the pin terminals 21 planted on one of the flanges 20 is wound around a conductive wire to form a primary winding 23 and a secondary winding 24. The lead wire 25 of the above is entangled with the pin terminal 21, and the entangled portion is solder-dipped to form a coil portion, and a magnetic core 26 made of a silicon steel plate or ferrite is incorporated into the coil portion to form a transformer body, A ferrite bead core 27 is inserted so as to penetrate the pin terminal 21, and is covered with a protective case 28 and a bottom plate 29 made of a non-magnetic material.

[0003]

[Problems to be solved by the device]

 In recent years, there has been remarkable progress in the widespread use of switching power supplies, and the switching frequency has been increasing year by year due to improvements in performance and miniaturization. Therefore, the noise generated from the switching power supply has many high-frequency components, and attention is being paid to its countermeasures.

In designing a switching power supply, as a measure against a noise problem, a resistance, a capacitor, an inductor, etc. are added to a circuit, a pattern wiring of a printed circuit board is changed, a power supply position in a set is changed, and a development design time is lost accordingly. However, in some cases, there was a problem that noise countermeasures would be prioritized even if the basic characteristics were slightly degraded.

Among various countermeasures against noise, as a means for absorbing noise due to a rectifying diode, which is particularly likely to cause noise, it is effective to add a ferrite bead core 27 to the circuit. This ferrite bead core 27 is inserted in series in the input and output lines of the transformer, and in order to reduce the number of additional parts, this ferrite bead core 27 is inserted in the pin terminal 21 of the transformer and built in the transformer. .

When a transformer incorporating the ferrite bead core 27 is configured, as a method of fixing the ferrite bead core 27 to the transformer, as shown in FIG. 5A, the ferrite bead core 27 is attached to the pin terminal 21 of the transformer. The ferrite bead core 27 is inserted into the printed circuit board or attached to the pin terminal 21, and then the ferrite bead core 27 is inserted into the protective case 28 and fixed by covering with the bottom plate 29. Further, as shown in FIG. 5B, a fixing projection 30 is provided on the bottom plate 29, and the projection 30 is hooked and fixed.

When the ferrite bead core 27 is inserted into the pin terminal 21 of the transformer as described above, the fixing of the transformer becomes unstable depending on the insertion state of the ferrite bead core 27, and the transformer floats above the printed circuit board. Sometimes it ends up. Furthermore, when the transformer body and the ferrite bead core 27 are covered by the protective case 28 and the bottom plate 29, the fixing of the transformer is stable, but depending on the type of the transformer, the height of the transformer is increased by inserting the ferrite bead core 27. There is a problem that ends up.

Further, since the ferrite bead core 27 made of a magnetic material is not an insulating material, the product conforming to the safety standard has a shorter insulation distance due to the ferrite bead core 27, so that some conventional products may not satisfy the safety standard. However, there is a problem that the pin terminal interval must be widened to secure the insulation distance in order to comply with the safety standard, and the shape becomes larger than the conventional product.

The present invention solves the above problems, and an object of the present invention is to provide a transformer in which a transformer is placed in a protective case, covered with a bottom plate containing a magnetic material, and pin terminals having an inductance component.

[0010]

[Means for Solving the Problems]

 In order to achieve this purpose, the present invention adopts a structure in which an inductance component is formed so as to penetrate the pin terminals by integrally molding or containing a magnetic material in the bottom plate. It constitutes a cover transformer.

[0011]

[Action]

 By integrally molding the magnetic material on the bottom plate of the transformer as described above, an inductance component is formed in the transformer pin terminals, and the same characteristics as when a ferrite bead core is inserted in the pin terminals are shown, reducing noise. It is possible to reduce the number of circuit parts to prevent noise.

[0012]

【Example】

 Example 1 An example of the present invention will be described below with reference to the drawings. FIG. 1 shows a cross-sectional view of a transformer according to an embodiment of the present invention. FIG. 2 shows an enlarged sectional view of the pin terminal portion of FIG.

In FIGS. 1 and 2, a coil bobbin 4 is formed by having a collar 3 at both ends of the winding frame portion 1, and a primary winding 6 wound around the winding frame portion 1 on one of the collars 3, A pin terminal 5 for arranging a lead wire 8 drawn from the secondary winding 7 is implanted. A primary winding 6 and a secondary winding 7 are respectively wound around the coil bobbin 4, the lead wire 8 is connected to the pin terminal 5, and electrically connected by solder dip or the like, and is made of a silicon steel plate or a ferrite core. The magnetic core 9 is incorporated to form the transformer body, and the bottom plate 13 made of plastic or the like is embedded and magnetic material 10 is integrally molded so as to form the ferrite bead core around the pin terminal insertion hole 12 of the bottom plate 13. A transformer case is formed by covering the transformer body with a protective case 11 made of a non-magnetic material.

With this configuration, an inductance component is formed in the pin terminal 5 by penetrating a magnetic material through the pin terminal 5 of the transformer, and it is possible to realize a bottom-back type noise reduction transformer and reduce the number of parts by noise countermeasures. it can.

Further, since the bottom plate 13 made of an insulating material such as plastic is molded so as to cover the magnetic material 10, the magnetic material 10 and the pin terminal 5 are insulated, and a product conforming to the safety standard can be provided.

Second Embodiment A second embodiment of the present invention will be described below with reference to the drawings. FIG. 3 shows a cross-section of a transformer in a second embodiment of the present idea. FIG. 4 is an enlarged cross-sectional view of the pin terminal portion of the transformer having insulation in the pin terminal insertion hole of FIG.

In FIG. 3, a transformer having the same structure as that of FIG. 1 is different from that of FIG. 1 in that a bottom plate 13 made of plastic or the like is molded by containing magnetic material powder, and the bottom plate 13 and plastic or the like are molded. The protective case 11 made of a non-magnetic material covers the transformer. Further, the bottom plate 13 formed by only the magnetic material 10 may be used.

Further, as shown in FIG. 4, by inserting an insulating ring 15 or the like into the pin terminal insertion hole 12 of the bottom plate 13 so as to have a specified insulation distance, the insulation between the pin terminal 5 and the magnetic material 10 can be obtained. It is possible to make it a product that conforms to the safety standard by adopting the structure with.

With this configuration, the magnetic material 10 penetrates the pin terminal 5 as in the first embodiment, and an inductance component is formed in the pin terminal 5, so that a bottom-back type noise reduction transformer can be realized. At the same time, parts can be reduced by taking measures against noise.

[0020]

[Effect of the device]

 As described above, according to the present invention, the bottom plate covering the transformer body contains the magnetic material, and the magnetic material penetrates the pin terminal to form the inductance component in the pin terminal, thereby providing the bottom back type noise reduction transformer. Furthermore, because the ferrite bead core is constructed simply by inserting the bottom plate, the number of parts for the ferrite bead core and the steps for external attachment can be reduced, resulting in excellent performance and productivity, and high reliability that complies with safety standards. It is possible to supply a transformer of a high degree and to realize a transformer of high industrial value.

[Brief description of drawings]

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

FIG. 2 is an enlarged sectional view of the pin terminal portion of FIG.

FIG. 3 is a sectional view of a transformer according to a second embodiment of the present invention.

FIG. 4 is an enlarged cross-sectional view of a pin terminal portion of a transformer in which the pin terminal insertion hole of FIG. 3 is insulated.

5A and 5B are cross-sectional views of a conventional transformer.

[Explanation of symbols]

 1 winding frame 2 ferrite bead core 3 collar 4 coil bobbin 5 pin terminal 6 primary winding 7 secondary winding 8 lead wire 9 magnetic core 10 magnetic material 11 protective case 12 pin terminal insertion hole 13 bottom plate 14 protrusion 15 insulating ring

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masayuki Mizushima, 1006 Kadoma, Kadoma, Osaka Prefecture, Matsushita Electric Industrial Co., Ltd. (72) Yoshihiro Kuniya, 1006, Kadoma, Kadoma, Osaka Prefecture, Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Scope of utility model registration request] 1. A transformer in which a coil portion is formed by winding a conducting wire around a coil bobbin having a collar at both ends of a winding frame portion and pin terminals being planted at at least one end, and a magnetic core is incorporated in the coil portion. A transformer in which the main body is inserted into a protective case, a magnetic material is integrally molded on a bottom plate having a hole through which the pin terminal penetrates, and the pin terminal is covered so as to penetrate. 2. The transformer according to claim 1, wherein a magnetic material is contained instead of the bottom plate integrally molded with the magnetic material.