JPH09213538A - Switching transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a structure of switching transformer which allows the dimension in the direction of its height to be reduced. SOLUTION: This transformer is structured such that a plurality of laterally risen terminal protrusions 6 and guide pins 5 integrally formed on the side face 1c of the base of a bobbin 1 round which a coil 2 is wound and the winding ends 2a of the coil guided along the side face 1c passing between the protrusions 6 and guide pins 5, and are bound and connected to lower lead terminals 7 of the protrusions 6. Rib 8 laterally risen from the side face 1c and run nearly horizontally are integrally formed of the base 1b to support the middle of the ends 2a with the ribs 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching transformer used in various electric devices, and more particularly, to a structure for treating a coil winding end.

[0002]

2. Description of the Related Art Generally, a switching transformer used in various electric devices is manufactured to have a structure as shown in FIGS. That is, although the coil 2A is wound and the pair of E-shaped cores 3A and 4A are attached to the upper bobbin portion 1a of the bobbin base 1A formed of an electrically insulating resin, the base portion 1b of the bobbin base 1A is attached. On the side surface 1c, a plurality of guide pins 5A for guiding the respective winding end portions 2a of the coil 2A and a terminal portion projection 6A are formed in a state of protruding laterally.

That is, the lead terminals 7A projecting from the bottom surface of the bobbin base 1A are integrally molded with the respective terminal portion projections 6A provided on the lower portion of the base portion 1b, and the winding end portions 2a from the coil 2A are separated from each other. In order to prevent a short circuit between the guide pins 5A and the corresponding terminal portion projections 6A, the lead terminals 7A are guided along the side surface 1c of the base portion 1b to the lead terminals 7A.
It is connected to the upper part of the corresponding lead terminal 7A by being twisted.

By the way, in the switching transformer having the above-mentioned structure, the length of the winding end 2a from the coil 2A to the lead terminal 7A is constant from the viewpoint of preventing a short circuit at the time of solder dipping. However, since each winding end portion 2a passing between the guide pin 5A and the terminal portion projection 6A is vertically guided along the side surface 1c of the base portion 1b, the bobbin base 1A is perpendicular to the base portion 1b. The directional dimension L1 is designed to be longer than the length required for the winding end 2a.

[0005]

However, in the conventional structure as described above, the base 1b of the bobbin base 1A is used.
Since the vertical dimension of the switching transformer is set to the length required for the winding end 2a, the vertical height of the switching transformer becomes large, and the vertical dimension required when the switching transformer is incorporated in the printed circuit board. There was a problem that it was difficult to reduce.

In view of the problems of the conventional switching transformer as described above, an object of the present invention is to obtain a structure capable of reducing the dimension of the switching transformer in the height direction.

[0007]

To achieve this object, the present invention integrally forms a plurality of terminal portion projections and guide pins that project laterally on the side surface of the base of a bobbin base around which a coil is wound. In a switching transformer in which the winding end of the coil guided along the side surface is connected to the lead terminal under the terminal projection through the gap between the terminal projection and the guide pin, from the side surface to the side. The present invention proposes a switching transformer in which a rib that is projected and extends in a substantially horizontal direction is integrally molded with the base portion, and the rib supports the intermediate portion of the winding end portion.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The details of the embodiment of the present invention will be described below with reference to FIGS. 1 and 2 show a switching transformer according to the present invention, in which a coil 2 is wound around a bobbin portion 1a on an upper portion of a bobbin base 1 formed of an electrically insulating resin to form a pair of E-shaped cores 3 and 4. On the side surface 1c of the base portion 1b of the bobbin base 1 which is mounted, a plurality of guide pins 5 for guiding each winding end portion 2a of the coil 2 and a terminal portion projection 6 are formed in a state of protruding laterally. Is the same as the conventional one.

A lead terminal 7 protruding from the bottom surface of the bobbin base 1 is integrally formed with each terminal portion projection 6 provided at the bottom of the base 1b, and the winding end portions 2a from the coil 2 are separated from each other. In order to prevent a short circuit between the corresponding guide pin 5 and the terminal portion projection 6, it is guided to the lead terminal 7 along the side surface 1c of the base portion 1b, and is connected to the upper portion of the corresponding lead terminal 7 by a tangled connection. Will be.

Further, according to the present invention, ribs 8 protruding laterally from the corresponding side surface 1c and extending substantially horizontally are integrally formed on both side surfaces 1c of the base portion 1b. That is, since the tips of these ribs 8 are located outside the lead terminals 7, when the winding end portions 2a are guided from the coil 2 to the lead terminals 7, the middle portions of the respective winding end portions 2a are to be guided. I will support you. Although the winding of the coil 2 is generally a three-layer insulated wire or a polyurethane wire, the winding is not limited to these.

Since the switching transformer according to the illustrated embodiment has the above-described structure, when each winding end portion 2a of the coil 2 is connected to the corresponding lead terminal 7 by wire connection, each winding end portion 2a serves as a guide pin 5. Although it is guided through the space between the terminal projections 6, the total length of the winding end 2a in this case is the length L2 from the coil 2 to the rib 8 and the rib 8 to the lead terminal 7. Up to the length L3. Therefore, the entire length of the winding end portion 2a can be kept sufficiently larger than the height dimension L4 of the base portion 1b of the bobbin base 1, so that the height dimension L4 of the base portion 1b is larger than that of the conventional one. The size of the switching transformer can be reduced, and as a result, it is possible to obtain a small-sized switching transformer with a reduced overall height dimension.

[0012]

As is apparent from the above description, according to the present invention, a rib is provided on the side surface of the base of the bobbin base and the rib supports the winding end of the coil. It is possible to obtain a small switching transformer with a reduced height dimension.

[Brief description of drawings]

FIG. 1 is a side view showing a cutaway part of a switching transformer according to the present invention.

FIG. 2 is an end view showing a cutaway portion of the switching transformer.

FIG. 3 is a side view showing a cutout of a conventional switching transformer.

FIG. 4 is an end view showing a cutaway portion of the switching transformer.

[Explanation of symbols]

 1 bobbin base 1b base 1c side 2 coil 2a winding end 3,4 E-shaped core 5 guide pin 6 terminal projection 7 lead terminal 8 rib

Claims (1)

[Claims] 1. A bobbin base around which a coil is wound is integrally molded with a plurality of terminal projections and laterally projecting terminal projections, and a winding end portion of the coil guided along the side surface is formed. In a switching transformer that is connected to a lead terminal below the terminal projection by passing between the terminal projection and a guide pin, a rib protruding laterally from the side surface and extending in a substantially horizontal direction is integrated with the base. A switching transformer characterized by being molded and having the rib supporting the intermediate portion of the winding end.