JPH0445218Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a transformer, and particularly to a transformer using an E-type core and an I-type core, or two E-type cores.

[Prior art]

In the conventional transformer as described above, a wire is wound around a cylindrical winding core made of an insulating material, the winding is wrapped around a pin terminal embedded in the winding core, and an E-shaped core is inserted through the winding core. , E-type or I-type cores are brought together to form a closed magnetic circuit.

FIG. 1 is an oblique view of an example of a conventional transformer using the above-mentioned E-type core and I-type core.
This transformer is made as follows. A winding coil is formed by applying a winding 2 to a cylindrical winding core 1 made of an insulating material, and connecting a winding lead wire to a pin terminal 3 implanted in the winding core, at the center leg of an E-shaped core 4. After passing through the I-type core 5, the end faces of each leg portion were brought together, and in this state, although not shown, an insulating tape was wound over both cores 4 and 5 to assemble and fix them. Therefore, there was a drawback that many steps were required for manufacturing. The same applies when an E-type core is used instead of an I-type core. In this case, the distance a between the cores 4 and 5 and the pin terminal 3 from which the winding 2 is drawn corresponds to the creepage distance defined in the safety standards, but as the transformer is downsized, the distance a is defined in the safety standards. It becomes impossible to secure a predetermined distance, for example, 3 mm. Therefore, in such cases, conventional methods have been to sandwich a multilayer insulating tape between the cores 4 and 5 so that it protrudes considerably to the outside, or to lengthen the creepage distance by protruding pleats on the creepage surface where the distance is a. After that, I wrapped it with insulating tape to assemble and fix it. However, as mentioned above, this also requires many steps, so the drawbacks for small transformers are even greater. In addition, in this type of transformer, since the outer surface of the core is exposed, there is a concern that it may come into contact with other components during high-density mounting on a board.

[Purpose of invention]

Therefore, the purpose of the present invention is to eliminate such drawbacks, easily and reliably maintain a predetermined creepage distance determined by safety standards between the core and the pin terminal, and to prevent the core from being exposed when facing outward. Furthermore, it is an object of the present invention to provide a transformer whose core can be easily assembled.

[Structure of the idea]

According to the present invention, a wire is wound around a cylindrical winding core made of an insulating material, the winding is wrapped around a pin terminal implanted in the winding core, and an E-shaped core is inserted into the winding core to form an E-shaped core. Alternatively, in a transformer in which I-shaped cores are brought together to form a closed magnetic circuit, a box-shaped core holder made of an insulating material that accommodates the E-shaped thick bottom portion including the corner portion of the core or the I-shaped core is provided. A transformer characterized in that a predetermined creepage distance is ensured between the pin terminal and the core is obtained.

〔Example〕

Examples of the present invention will be described below.

FIG. 2 is an exploded perspective view for explaining the process of assembling the core of a transformer according to an embodiment of the present invention. 1 to 5 represent the same things as in FIG. The holders 6 and 7 are made of a flexible insulating material such as synthetic resin, and are box bodies having a space large enough to cover the thick bottom parts including the corners of the abutted cores 4 and 5. The depth b, together with the distance a shown in FIG. 1, is set so as not to be less than the creepage distance determined by safety standards. This point will be explained in detail later. The holder 6 has a core fixing tongue piece integrally formed with the box body along the outer surface of the core outer leg portion, and a locking claw 61 is provided on the tongue piece. The holder 7 has a locking claw hole 7 corresponding to the locking claw 61 in the core fixing tongue piece.
1 is provided. Further, a spring 8 for fixing and holding the core is inserted between the holder 6 and the outer surface of the thick bottom portion of the core. The core 4 is held by such holders 6 and 7.
and 5 constitute a closed magnetic path. When assembling the transformer according to the present invention, the spring 8 is placed inside the box of the holder 6.
and attach the holders 6, 7 to the outer surface of the bottom thick part of the cores 4, 5.
Place it on the opening and press it. The locking pawl 61 and the locking pawl hole 71 prevent the holders 6 and 7 from coming off the core, and the spring 8 bends to maintain the fixation of the core by the holders 6 and 7. The core is thus almost completely sealed from the outside.

FIG. 3 is a side sectional view of one implementation of the present invention. The core 4,
The creepage distance between the pin terminal 5 and the pin terminal 3 is measured as a+b, which ensures the creepage distance determined by safety standards and almost completely eliminates the exposed surface to the outside.

[Effect of idea]

As explained above, the transformer according to the present invention can easily and reliably secure the creepage distance between the core and the pin terminals, and can avoid contact with other components when mounting boards at high density. There is also no need to wrap insulating tape around the core, which has the advantage of simplifying work and reducing man-hours.

[Brief explanation of drawings]

Figure 1 is a perspective view showing the structure of a conventional transformer, Figure 2 is an exploded perspective view illustrating the assembly process of a transformer that is an embodiment of the present invention, and Figure 3 is an embodiment of the present invention. FIG. Explanation of symbols: 1 is the winding core, 2 is the winding wire, 3 is the pin terminal, 4 is the E-type core, 5 is the I-type core, 6 and 7 are the holders made of insulating material, 8 is the spring, and 61 is the lock. The claws 71 each represent a locking claw hole.

Claims (1)

[Scope of utility model registration request] A winding is applied to a cylindrical winding core made of an insulating material, the winding is wrapped around a pin terminal implanted in this winding core, and an E-type or I-type core is attached by penetrating the winding core with an E-type core. In the transformer that also constitutes a closed magnetic circuit, a box-shaped core holder made of an insulating material that accommodates the E-shaped bottom thick part including the corner part of the core or the I-shaped core is provided, and the pin terminal A transformer characterized by ensuring a predetermined creepage distance between the core and the core.