JPS6242507A - High-frequency coil - Google Patents

Abstract

PURPOSE:To widen the variable range by a method wherein a pot core is separated from a screw core to allow them to be separately controlled, thereby increasing the adjustment accuracy of inductance with a simplified structure. CONSTITUTION:A screw core 17 on whose circumference, screw section 16 is formed, is screwed in the hollow section 15 of a bobbin with self-tapping. A adjustment rod 18 is formed on this core 17. The position of rod 18 to a coil 12 can be adjusted by rotating the rod 18 through a transparent window 20 on the surface of a ceiling of a shielding case 19 with a driver. On the other hand, a pot core 25 having an adjustment rod 27 on the upper surface and a through hole 28 on the center is screwed in a core holding mold 23. The rod 28 and a core 25 having the through hole 28 on the center are rotated by a rod 27 with a driver to control the position to the coil 12.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a high frequency coil having a variable inductance mechanism used in electronic equipment such as televisions and videos.

2. Prior Art A conventional high frequency coil of this type is, for example,
As shown in Publication No. 746, it had a structure as shown in FIG.

That is, a bobbin 6 having a plurality of flanges 4 around which the coil 3 is wound is formed on the upper surface of the central part of the terminal board 2 on which the terminal 1 is implanted, and the terminal board 2 is covered with a shield case 6. A core holding mold 7 whose lower end is in contact with the side surface of the terminal plate 2 is disposed on the inner wall of the bobbin 6, and a pot core 8 having a core inserted into the bobbin 5 is screwed into this core holding mold door. There is.

An adjustment groove 9 was formed on the upper surface of this pot core 8, and the position with respect to the coil 3 could be controlled by rotating the pot core 8 with a driver or the like.

Problems to be Solved by the Invention However, with such a structure, when adjusting the inductance of the coil 3 by rotating the pot core 8 with a core, the amount of change in inductance with respect to the rotation angle of the pot core 8 with a core is This makes it difficult to accurately adjust the inductance, and furthermore, it is not possible to widen the variable range of the inductance.

Therefore, the present invention aims to increase the accuracy of inductance adjustment and widen the variable range with an extremely simple structure.

Means for solving the problems and technical means of the present invention for solving the above problems are as follows:
Instead of a pot core with a core, a screw core is screwed into the hollow part of the bobbin, and a pot core with a screw part formed on the outer peripheral surface, an adjustment groove on the top surface, and a through hole in the center is screwed into the core holding mold. That is.

action The effect of this technical means is as follows.

In other words, the screw core in the bobbin hollow part and the pot core, which has an adjustment groove and a through hole in the center, rotate separately, so
If one core is fixed and the other core is rotated, the amount of change in inductance with respect to the rotation angle is smaller than in the past, and the inductance adjustment accuracy can be increased.

Further, since the screw core rotates from the bottom of the bobbin to the top, and the pot core, which has an adjustment groove and a through hole in the center, rotates from the top of the bobbin to the ceiling of the shield case, the range of variable inductance becomes wide. .

Embodiment Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings.

In FIG. 1, the lower part of a hollow bobbin 14 provided with a plurality of flanges 13 around which a coil 12 is wound is press-fitted into the center of a terminal plate 11 having a terminal 10 implanted therein.

This hollow bobbin 14 is molded from a thermoplastic resin such as polypropylene or polycarbonate, and the bobbin hollow part 16 has a threaded core 1 having a threaded part 16 formed on the outer peripheral surface.
7 are screwed together by self-tapping. An adjustment groove 18 is formed in this screw core 17, and the shield case 1
Rotate the screw core 17 using the adjusting groove 18 with a screwdriver or the like through the through hole 20 in the ceiling surface of the coil 1.
The structure is such that the position relative to 2 can be controlled.

Then, the terminal board 11 is covered with a shield case 19,
This shield case 19 is provided with a projection 22 that engages with the lower part of the step 21 of the terminal board 11. Terminal board 11
The stepped portion 21 fits into the stepped portion fixing hole 24 provided in the core holding mold 23, and the terminal plate 11 and the core holding mold 23 are
Fixed.

The upper part of the core holding mold 23 is in contact with the ceiling of the shield case 19, and the lower part is mechanically fixed because the lower part of the step part 21 of the terminal board 11 is pressed against the protrusion 22 of the shield case 19.

The core holding mold 23 is disposed on the inner wall of the shield case 19 so that its lower end is in contact with the side surface of the terminal plate 11, and is made of thermoplastic resin. This core holding mold 2
A pot core 25 having an adjustment groove 27 on the upper surface and a through hole 28 in the center is screwed into the pot core 3 . A threaded portion 26 is formed on the outer circumferential surface of the pot core 26 which has a through hole 28 in the center thereof, and this threaded portion 26 is screwed into the core holding mold 23 by self-tapping. The pot core 26 having a through hole 28 at its center is rotated using the adjustment groove 27 with a screwdriver or the like, so that its position relative to the coil 12 can be controlled.

When the screw core 17 of the bobbin hollow part 15 is rotated in this way, the pot core 26 having the through hole 28 at the center of the adjustment groove 2 is fixed, or the screw core 17 is fixed and the hole passes through the adjustment groove 2 and the center. By rotating the pot core 26 having the hole 28, the amount of change in inductance with respect to the rotation angle becomes smaller than that in the structure of the pot core with a core. Furthermore, the variable range of inductance changes when the screw core 17 is rotated depending on the position of the adjustment groove 27 and the pot core 26 having a through hole 28 in the center, so the range of change is wider than that of a pot core structure with a core. Become.

Effects of the Invention As described above, the present invention has an extremely simple configuration in which the pot core and screw core are separated and can be controlled separately.
It has the effect of increasing the precision of inductance adjustment and widening the variable range, and is of great industrial value.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a high-frequency coil according to an embodiment of the present invention, FIG. 2 is a perspective view of a pot core having adjustment grooves and a through hole in the center of the present invention, and FIG. 3 is a view of a conventional high-frequency coil. FIG. 1o...Terminal, 11...Terminal board, 12
...Coil, 13...Tsuba, 14...
...Bobbin, 15...Hollow part, 16...
...Screw part, 17...Screw core, 18...
...Adjustment groove, 19...Shield case, 20.
River...through hole, 21...step, 22...
Projection, 23...Core holding mold, 24...
...Stepped fixing hole, 25...Pot core, 2
6...Threaded part, 27...Adjustment groove, 28
......Through hole. Name of agent: Patent attorney Toshio Nakao and one other name
1 Illustration night 3r! ! J

Claims (1)

[Claims] A bobbin wound with a coil made of thermoplastic resin is connected to the center upper surface of a terminal plate mechanically connected to the lower part of the shield case, and the lower end is brought into contact with the terminal plate to hold the core made of thermoplastic resin. A high-frequency coil is formed by arranging a mold, screwing a pot core with adjustment grooves and through holes on the upper surface into the core holding mold, and screwing a screw core into a hollow part of a coil bobbin.