JPS6031221Y2 - intermediate frequency transformer - Google Patents

Description

[Detailed description of the invention] The present invention relates to an intermediate frequency transformer used in radio equipment such as a radio receiver, and more specifically, a driver for adjusting the inductance of the intermediate frequency transformer provided in the cap core, which is a component of the transformer. The present invention relates to an intermediate frequency transformer in which the engaging portion of a tool such as the above is formed as an opening passing through the inner and outer surfaces of the end face, thereby reducing the wall thickness of the end face, thereby reducing the overall size and weight.

FIG. 1 is a sectional view showing an example of a commonly used intermediate frequency transformer.

In the figure, a drum core 1 is made of ferrite or the like and has a shape that combines cylinders with different diameters.
The small diameter portion at one end is inserted into the through hole of the substrate 2, and the large diameter portion is fitted into the inner periphery of the cylindrical portion that is the body of the substrate 2.

A coil 3 is attached to the outer periphery of the small diameter part near the center of the drum core 1.
is installed.

A bobbin 4 is fixed to the outer periphery of the cylindrical portion of the substrate 2,
A screw 4a is provided on the outer periphery of the bobbin 4.

The cap core 5 made of ferrite or the like has a cylindrical shape with an end face at one end, and a screw 5a screwed into the inner periphery of the cylinder at the other end, which engages with a screw 4a provided on the outer periphery of the bobbin 4. is provided.

A driver groove 5b for adjusting inductance is provided on the outer periphery of the end surface of the cap core 5.

When an adjustment tool such as a screwdriver is engaged with the groove 5b and the cap core 5 is rotated, the cap core 5 is moved in the vertical direction in the figure by the action of the screws 5a and 4a, and the inductance is adjusted.

In the figure, 6 is a shield case, and 7 is a donut-shaped capacitor.

2. Description of the Related Art Recently, as radios, televisions, etc. have become smaller, the components used in these devices are also required to be smaller.

Naturally, the intermediate frequency transformer is also required to be miniaturized, and therefore its component parts must also be miniaturized.

Naturally, the cap core, which is a component of the intermediate frequency transformer, is also required to be thin and flat.

FIG. 2A is a front view of a conventionally used cap core 5, and the opening is a plan view thereof.

In the figure, in order to make the cap core 5 thin and flat, it is necessary to reduce dimensions B and C.

However, since the groove 5b must transmit the rotational force of a tool such as a screwdriver to the cap core 5, it requires a certain depth.

That is, the dimension A cannot be lower than a certain value.

In addition, since force is applied to the bottom of the groove 5b by the tip of the tool, there is a risk of damage if the wall thickness is not over a certain value, and if the value of A/B is increased beyond a certain value, cracks may occur in the bottom mold. Easy to enter.

That is, in the conventional cap core 5, the 8th dimension could not be made smaller than a certain level, and therefore the C dimension could not be made smaller than a certain level, so there was a drawback that it could not meet the demands for thinning and flattening.

The present invention aims to eliminate the above-mentioned drawbacks of conventional intermediate frequency transformers and to provide an intermediate frequency transformer that can be made smaller, lighter, and flatter.

The present invention is distantly related to the above-mentioned object by making the retaining portion of the inductance adjustment tool such as a screwdriver provided on the end face of the cap core as an opening passing through the inner and outer surfaces of the end face.

Embodiments of the present invention will be described below based on the drawings.

FIG. 3A is a front view showing an embodiment of the cap core according to the present invention, and the opening is a plan view thereof.

In both figures, a through hole 5c is bored in the end face of the cap core 5, and by inserting and surrounding the protrusion 10a provided on the end face of the driver 10 as shown in FIG. 4 into this through hole, the inductance can be adjusted. I can do it.

FIG. 5A is a front view showing another embodiment, and the mouth is a plan view thereof.

In both figures, a through hole i5d is provided on the end surface of the cap core 5.

The inductance can be adjusted by inserting the tip of a regular screwdriver into this groove 5d and surrounding it.

In both of the above-mentioned two embodiments, the thickness B of the end surface of the cap core 5 (see FIG. 3A and FIG. 5A) is such that the rotational force of a tool such as a screwdriver is transmitted to the cap core 5. Since it is sufficient to have a sufficient dimension for the cap core 5, the required minimum value of the dimension A (see Fig. 2 A) in the conventional example is sufficient. Therefore, the dimension C can also be made small, so the cap core 5 can be made flat and thin. This allows the intermediate frequency transformer to be made smaller and lighter.

Furthermore, there is no fear of cracks occurring during molding, particularly at the bottom of the grooves, which has been a drawback of the prior art.

As described above, the present invention greatly contributes to the reduction in size and weight of radios, televisions, and other wireless equipment by providing a small and lightweight intermediate frequency transformer.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an example of a commonly used intermediate frequency transformer, Fig. 2 (a) shows a front view and a plan view showing the cap core, and Fig. 3 (a) shows a front view of the cap core according to the present invention. FIG. 4 is a diagram showing the shape of the driver, and FIG. 5 is a front view and a plan view showing another embodiment of the present invention. 1... Drum core, 2... Board, 3.
...Coil, 4...Bobbin, 5...
・Cap core.

Claims (1)

[Scope of utility model registration request] In an intermediate frequency transformer comprising a drum core equipped with a coil, a cap core having a threaded portion, and a fixing member screwed to the cap core, an end surface of the cap core is provided with a through opening for engaging a main part of an adjustment tool. , an intermediate frequency transformer characterized by easy inductance adjustment.